Design Guide for Low-Speed Multimodal Roadways (2018)

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40 3.1 Performance for Multimodal Projects Performance measures promote informed decision making by relating community goals to the measurable effects of transportation investments. Key steps in developing performance mea- sures are (1) deciding what to measure to capture the current state of the system, (2) setting tar- gets to improve those measures and (3) using the measures to evaluate and compare the effects of proposed project alternatives. For a project, performance measures can include a wide range of multimodal criteria (e.g., capacity, mobility, safety, accessibility, comfort, reliability). Performance measures also can include unique operations measures that are identified for each mode by user or mode (e.g., travel speed, delay, crash potential, convenience, accessibility, LOS, QOS). From a purely safety perspec- tive, performance measures for each mode may be identified, such as expected number of total crashes or crashes by severity, expected number of fatalities and injuries (by severity), expected number of crashes by collision type, crash exposure, and so forth. From a sustainable trans- portation perspective, performance measures could include transit accessibility/productivity, bicycle/pedestrian mode share, vehicle-miles traveled (VMT) per capita, levels of “bikeability” or “walkability,” aesthetics, air quality impacts, and so forth. Many of these measures need to be classified according to whether they are multimodal or mode-specific, and guidance is needed on how the measures should differ depending on the roadway speed range (i.e., low, intermediate, or high speed), roadway functional classification and context. For street and road projects that will blend multimodal users in low- and intermediate-speed environments, it is advised that performance measures be developed for all existing and pro- jected users as well as for all identified sustainable and community goals. Safety should always be a key element of this analysis; the risk of fatal or severe injury to non-motorized users is signifi- cant in all vehicle environments but especially in higher speed environments (above 25 mph). Only through carefully defined performance metrics can the designer understand and project the impacts of design choices on all modes in a project. 3.1.1 Increased Demand for Pedestrian, Bicycle and Transit Performance Measures As more agencies design transportation projects that include improvements for walking, bicycling and transit accommodation, they are increasing their efforts to understand and estab- lish performance measures and metrics that address all these modes. Most transportation agen- cies have routinely relied on vehicle-based performance metrics from the HCM to assess the effectiveness of improvement designs for motorized travel, but the evolving tools and processes C H A P T E R 3 Balancing User Performance in Low- and Intermediate-Speed Environments

Balancing User Performance in Low- and Intermediate-Speed Environments 41 available to assess the needs and service levels of non-motorized users have been more elusive and ultimately difficult to use. Capacity, LOS, delay and stops are easily applied to define and assess vehicular performance for a planned roadway, but no predefined set of performance metrics can fully describe the safety and mobility complexities that exist given the interrelationships that exist between and among modes in the right-of-way. In a constrained funding environment, it is critical to be able to identify the project scope and which investments will provide the highest level of benefit to the most users in a roadway corridor, segment or intersection. Consequently, more agencies are applying multiple transportation performance measures—in various ways and using various scales—throughout the transportation design process. Performance management also plays a central role in federal, state, regional and local trans- portation planning, funding and design. Since 2015, the FAST Act “has required state DOTs and MPOs to consider non-motorized users in long-range statewide transportation plans (LRSTP) and metropolitan transportation plans (MTP).” The FAST Act also stipulates that these plans must include a description of the performance measures and performance targets used in assess- ing the performance of the transportation system and a system performance report evaluating the condition and performance of the transportation system. This Guide is intended to help designers better understand, select and apply performance measure tools for a variety of project design elements, controls and criteria. Although some transportation performance measures are useful for tracking and measuring progress toward related, broad community goals such as health and economic development, the measures addressed in these guidelines focus on mobility, accessibility, QOS, safety and reliability out- comes from design choices. Critical steps in performance management are (1) deciding what to measure to capture the current condition of the facility from all user perspectives, (2) setting targets that improve those measures, and (3) using the measures to evaluate and compare the effects of project design alternatives. 3.2 Assessing Performance, LOS and QOS for All Users Conventional roadway design has traditionally attempted to provide the highest practical vehicular LOS for a project. Conversely, designing roadways for all users takes vehicle traffic projections and LOS into account but also evaluates LOS and QOS for non-motorized users. It then balances the needs of all legal users of the roadway, and may even emphasize one or more users over others depending on the context, purpose and need of the project (e.g., a project may reduce vehicle lanes to accommodate bicycle lanes, on-street parking or wider sidewalks). While vehicular capacity and LOS certainly play an important role in selecting design criteria, they are only two of numerous factors a designer should consider and prioritize in the design of roads and streets with a mix of users. Often in urban and urban core areas, roadway capacity is considered a lower priority than factors such as non-motorized user safety and higher levels of accessibility for transit, pedestrian or bicycle travel, facilitating economic development, or preserving historical features. In those situations, the community may consider lower levels of vehicle service (e.g., higher levels of vehicle inconvenience or congestion) acceptable. LOS and QOS for all users often is a priority project design objective for local agencies or communities, but it may require variances or exceptions from the adopted design or performance standards of partner agencies (e.g., FHWA or a state DOT). The geometric design of a street or roadway project typically begins with an assessment of the purpose and need of the project. This purpose and need can be determined informally or formally through environmental process documentation. Normally established goals and

42 Design Guide for Low-Speed Multimodal Roadways outcomes will address, at some level, the desired performance of the new or redesigned facility. Traditionally, these goals and outcomes have focused on the LOS and safety provided to motor- ized vehicles; more recently, both the LOS and QOS are being considered for all legal users of that facility, using a wide range of possible performance measures. 3.2.1 Performance Measures From an operational perspective, the LOS criterion for motorized vehicles from procedures defined in the HCM traditionally has served as the primary performance measure for evaluat- ing the quality of alternative roadway designs. However, approaches to assessment of LOS have been impacted by: • Performance-based design research; • Development of alternative approaches to multimodal LOS; • Publication of the HSM (AASHTO 2010) and supplementary information; • Numerous state and local guidelines for complete street design; and • Extensive information on context-sensitive design solutions and design flexibility. As a result, a recognized need exists to identify performance measures that can be used to evaluate the design alternatives for a roadway project based on how it meets the overall needs and safety of all users and modes: automobile/truck, pedestrian, bicyclist and transit user. Additionally, given the interactions of the various modes in a project, improvements made to the LOS or QOS for one mode may improve or lower the LOS or QOS for one or more of the other modes. Today, geometric designers can use a wide variety of tools to assess the performance, LOS and QOS for all modes operating on all types of roadways, including low- and intermediate-speed streets. These tools range from detailed quantitative processes in the HCM that require field data collection and mathematical analysis, to more simple and qualitative methods such as the bicycle level of service (BLOS) model (Sprinkle Consulting 2007) and the Pedestrian Environ- mental Quality Index (PEQI) developed by the San Francisco Department of Public Health (San Francisco Department of Public Health 2012). The HSM is providing ever-increasing guidance to designers on the safety implications of design choices affecting all modes. These and the other available tools offer designers choices for evaluating street design alternatives and guide future improvement decisions. However, the ability of most of these tools to measure the effectiveness of combinations of multimodal design accommodations, including evolving innovative treatments such as separated bicycle tracks and bicycle-protected intersections, has been limited. As a result, many agencies and designers employ a variety of tools and strategies in assessing LOS and QOS, and often employ a wide range of performance-based design measures beyond LOS and QOS. 3.2.2 Current Practice The leading geometric design LOS tool used by roadway design agencies has traditionally been the HCM (2010 edition) and its analysis software. In response to the increasing need to estimate performance measures related to pedestrian, bicycle and transit facilities, as well as their interac- tions with vehicle facilities, the HCM 6th Ed. (subtitled A Guide for Multimodal Mobility Analysis) provides several new and improved assessment tools and methods. Chapters 16–23 of the HSM include methods for assessing non-motorized modes and their interactions with vehicular traf- fic, whereas Chapter 24 provides methods for analyzing off-street pedestrian and transit facilities. Chapter 15 provides a methodology for evaluating bicycle operations on multilane and two- lane highways. The HCM considers the effects of transit presence along urban streets within its multimodal analysis framework. A companion document to the HCM, the Transit Capacity and

Balancing User Performance in Low- and Intermediate-Speed Environments 43 Quality of Service Manual (TCQSM), now in its third edition, focuses on the evaluation of transit facilities (Kittelson and Associates, Inc., et al. 2013). Many agencies and design professionals have considered the 2010 HCM analysis to be the most comprehensive and thorough LOS procedure available, but many users have also expressed concern with the difficulty in using this tool to analyze multimodal level of service (MMLOS) and concerns about the relationship of its bicycle, pedestrian and transit LOS and QOS findings to actual field conditions and user group perceptions. In practice, the HCM tools have been used routinely for evaluating and designing the motorized-vehicle elements of street and roadway design projects, whereas the multimodal analysis tools have been used much less frequently. Most design professionals know that these HCM tools exist, but the multimodal analysis methods appear to have been selectively used for larger, more complex projects that involve major invest- ment (e.g., lengthy corridor improvements). The newer multimodal analysis guidance included in the HCM 6th Ed. may be considered more effective and used more often by designers to evaluate multimodal design alternatives. Given the relatively short time the HCM 6th Ed. has been available for use, however, little has been published by practitioners about the real-world applicability and ease of use of the new multimodal analysis tools. The designer also must consider how the selected LOS, QOS and other performance mea- sures for a project should be used collectively to evaluate alternative geometric design options. A full range of methodologies may be considered, from simple qualitative approaches to more complex approaches (e.g., combining multiple performance measures into a combined weighted index for evaluation purposes). Additionally, the impact of a design choice on infre- quent but important users (e.g., emergency response vehicles, commercial service vehicles, large freight trucks) needs to be factored into the overall procedures for evaluating design alternatives. Similarly, design choices can have significant impacts on various users traveling by other modes. For example, the mix of pedestrians (e.g., children, adults of various ages, and persons with disabilities) may vary by location, and design choices may need to incorpo- rate ADA and other guidelines accordingly. Similarly, the types of bicyclists (e.g., commuter, school, recreational, etc.) and the effectiveness of different types and levels of transit service (e.g., local bus, bus rapid transit [BRT], trolley/streetcar, light rail, and so forth) need to be considered. 3.2.3 Evolving Guidance for Assessing Multimodal Performance in the Design Process In recent years, the profession has developed an increasing amount of literature and research to improve performance-based planning and design for all modes served by transportation proj- ects and address the needs of all users. Many agencies and project designers have been challenged to stay abreast of this rapidly evolving guidance and incorporate it properly into their agency policies, standards and processes. The leading guidance documents currently available to designers in assessing and guiding design for multimodal performance are: • Guidebook for Developing Pedestrian and Bicycle Performance Measures (FHWA 2016c). As described in the report abstract, [t]his guidebook is intended to help communities develop performance measures that can fully inte- grate pedestrian and bicycle planning in ongoing performance management activities. It highlights a broad range of ways that walking and bicycling investments, activity, and impacts can be measured and documents how these measures relate to goals identified in a community’s planning process. It discusses how the measures can be tracked and what data are required, while also identifying examples of com- munities that are currently using the respective measures in their planning process.

44 Design Guide for Low-Speed Multimodal Roadways The FHWA guidebook expands the concept of performance measures specifically for pedestrian and bicycle transportation and identifies a toolbox of 30 specific performance measures mapped to seven broader project goal categories: connectivity, economic, envi- ronment, equity, health, livability and safety. The guidebook notes that pedestrian and bicycle transportation are considered “critical to each of these goal categories, and many performance measures are useful in characterizing a community’s transportation system’s ability to further the community goals.” The FHWA guidebook highlights the “universe of possibility” for pedestrian and bicycle performance measures, enabling communities at the local, regional and state levels to select from among these measures and “develop a performance management strategy that is tailored to their context and unique needs” (FHWA 2016c). Many transportation agencies focus on transportation-specific goals (e.g., mobility and accessibility), which can be used to describe the transportation system and help set policies and priorities. However, individual transportation goals and performance measure categories often relate to more than one of the broader community goals. As discussed in the guidebook, accessibility helps connect buyers and sellers (thus contributing to economic goals) while also supporting a community’s livability. The guidebook also lists transportation measures that support one or more community goals (FHWA 2016c): • Accessibility: Refers to access for people with disabilities to programs, services, and activities. • Compliance: Conforming to a requirement, e.g., a statute or regulation. • Demand: The amount of existing and potential future walking and bicycling activity. • Reliability: Refers to the degree of certainty and predictability in travel times on the transportation system. • Mobility: The ability of all users to travel or move from place to place. • Infrastructure: All the relevant elements of the environment in which a transportation system operates, including streets, signals, bridges, transit, bike facilities, shared-use paths, and sidewalks. • Highway Capacity Manual (HCM), Sixth Edition: A Guide for Multimodal Mobility Analy- sis (TRB 2016b). The HCM 6th Ed. provides methods for quantifying highway capacity and is described on the Transportation System Preservation Technical Services Program (TSP•2) webpage as follows (TSP•2 2016): In its current form, it serves as a fundamental reference on concepts, performance measures, and analysis techniques for evaluating the multimodal operation of streets, highways, freeways, and off-street pathways. The 6th Edition incorporates the latest research on highway capacity, quality of service . . . and travel-time reliability and improves the HCM’s chapter outlines. The objective is to help practitioners applying HCM methods understand their basic concepts, computational steps, and outputs. . . . HCM has evolved over the years to keep pace with the needs of its users and society, as the focus of surface transportation planning and operations in the United States has moved from designing and constructing the Interstate highway system to managing a complex transportation system that serves a variety of users and travel modes. Providing mobility for people and goods is transportation’s most essential function. It consists of four dimensions: • Quantity of travel, the magnitude of use of a transportation facility or service; • Quality of travel, users’ perceptions of travel on a transportation facility or service with respect to their expectations; • Accessibility, the ease with which travelers can engage in desired activities; and • Capacity, the ability of a transportation facility or service to meet the quantity of travel demanded of it. Chapters in the HCM 6th Ed. also provide methods that address the increasing need to estimate performance measures related to pedestrian, bicycle and transit facilities and the interactions of these modes with vehicles. Chapters 15–23 and Chapter 25 address analyz- ing off-street pedestrian and transit facilities, evaluating bicycle operations on multilane and two-lane highways, and assessing non-automobile modes and their interactions with vehicular traffic.

Balancing User Performance in Low- and Intermediate-Speed Environments 45 Using the HCM 6th Ed. for pedestrian and bicycle analysis on urban streets can require significant data collection and analysis. The guidebook provides three pedestrian perfor- mance measures for urban street segments and facilities: (1) space, reflecting the density of pedestrians on a sidewalk, (2) speed, reflecting intersection delays, and (3) a pedes- trian LOS (PLOS) score, reflecting pedestrian comfort with the walking environment (TRB 2016b). Exhibit 3-1 lists the data required for these measures and provides suggested default values. The HCM provides two bicycle performance measures for urban street segments and facilities: average travel speed (reflecting intersection delays) and a bicycle LOS (BLOS) score (reflecting bicyclist comfort with the bicycling environment). Exhibit 3-2 lists the data required for these measures and provides suggested default values. • NCHRP Report 825: Planning and Preliminary Engineering Applications Guide to the Highway Capacity Manual (Dowling et al. 2016). This guide will help designers apply the methodologies of the HCM 6th Ed. “to common project planning and preliminary engineer- ing analyses (including scenario planning and system performance monitoring). It shows how the HCM can interact with travel demand forecasting, mobile source emission, and For For For Input Data (units) SPC SPD PLOS Default Value Sidewalk width (ft.) • • • 12 (CBD), 5 (other) Effective sidewalk width (ft.) • • 8.5 (CBD), 3.5 (other) Bi-directional pedestrian volume (ped./h.) • • Must be provided Free-flow pedestrian speed (ft./sec.) • • • 4.4 Segment length (ft.) * • • Must be provided Signalized intersection delay walking along street (sec.) * • • See Section O5 or use 12 (CBD), 30 (suburban) Signalized intersection delay crossing street (sec.) * • See Section O5 or use 12 (CBD), 50 (suburban) Outside lane width (ft.) * • 12 Bicycle lane width (ft.) • 0 Shoulder/parking lane width (ft.) • 1.5 (curb and gutter only) 8 (parking lane provided) Percentage of segment with occupied on-street parking (decimal) • 0.00 (no parking lane) 0.50 (parking lane provided) Street trees or other barriers (yes/no) ** • No Landscape buffer width (ft.) • 0 (CBD), 6 (other) Curb presence (yes/no) • Yes Median type (divided/undivided) • Undivided Number of travel lanes * • Must be provided Directional vehicle volume (veh./h.) * • Must be provided Vehicle running speed (mph) * • Intersection PLOS score (unitless) • See Section K6 or use the posted speed Calculated, see Section O5 Average distance to nearest signal (ft.) • One-third the segment length Section numbers refer to content in NCHRP Report 825. See HCM 6th Ed., Chapter 18, for definitions of the required input data. SPC = space; SPD = speed; PLOS = pedestrian LOS; CBD = central business district. * Input data used by or calculation output from the HCM urban street motorized vehicle LOS method. ** Street trees, bollards, or other similar vertical barriers 3 ft. or more tall, or continuous barrier at least 3 ft. tall. Source: From Exhibit 98 in NCHRP Report 825 (Dowling et al. 2016) Exhibit 3-1. Required data for urban street pedestrian analysis.

46 Design Guide for Low-Speed Multimodal Roadways simulation models and its application to multimodal analyses and oversaturated conditions. In addition to providing a cost-effective and reliable approach to analysis, the guide provides a practical introduction to the detailed methodologies of the HCM.” • AASHTO’s Highway Safety Manual (HSM) (AASHTO 2010). The purpose of the HSM is to provide the best information and proven analysis tools for crash frequency prediction. The manual focuses on the “increased application of analytical tools for assessing the safety impacts of transportation project and program decisions.” The HSM can be used in the proj- ect design process to (FHWA 2014e): • Identify factors contributing to crashes and associated potential countermeasures to address these issues. • Evaluate the crash reduction benefits of implemented treatments [. . .]. • Calculate the effect of various design alternatives on crash frequency and severity. The HSM also includes an Interactive Highway Safety Design Model (IHSDM), a suite of software analysis tools for evaluating safety and operational effects of geometric design decisions (FHWA 2003). It provides estimates of a highway design’s expected safety and operational per- formance and checks existing or proposed highway designs against relevant design policy values. Chapter 12 in the HSM provides a structured methodology for estimating the predicted and/or expected average crash frequency, crash severity, and collision types for urban and sub- urban arterial facilities. Crashes involving all vehicle types, bicycles, and pedestrians are included, except for crashes between bicycles and pedestrians. The methodology is applicable to existing sites, design alternatives to existing sites, new sites, and alternative traffic volume projections. Chapter 12 can be applied to all arterials located inside urban areas that have a population For For Input Data (units) SPD BLOS Default Value Bicycle running speed (mph) • 12 Signalized intersection delay (s) • • See Section O5 or use 10 (CBD), 22 (suburban) Segment length (ft.) * • • Must be provided Bicycle lane width (ft.) ** • 5 (if provided) Outside lane width (ft.) ** • 12 Shoulder/parking lane width (ft.) ** • 0 (curb and gutter only) 8 (parking lane provided) Percentage of segment with occupied on-street parking (%) ** • 0 (no parking lane) 50 (parking lane provided) Pavement condition rating (1–5) • 3.5 (good) Curb presence (yes/no) ** • Yes Median type (divided/undivided) ** • Undivided Number of travel lanes * • Must be provided Directional vehicle volume (veh./h.) * • Must be provided Vehicle running speed (mph) * • See Section K6 or use the posted speed Percentage heavy vehicles (%) * • 3% Access points on the right side (points/mi.) • 17 (urban arterial), 10.5 (suburban arterial), 30.5 (urban collector), 24 (suburban collector) Intersection BLOS score (unitless) • Calculated, see Section O5 Section numbers refer to content in NCHRP Report 825. See HCM 6th Ed., Chapter 18, for definitions of the required input data. SPD = speed; BLOS = bicycle LOS; CBD = central business district. * Input data used by or calculation output from the HCM urban street motorized vehicle LOS method. ** Input data used by the HCM urban street PLOS method. Source: From Exhibit 101 in NCHRP Report 825 (Dowling et al. 2016) Exhibit 3-2. Required data for urban street bicycle analysis.

Balancing User Performance in Low- and Intermediate-Speed Environments 47 greater than 5,000. The chapter includes arterials other than freeways without full access control with two- or four-lane undivided facilities, four-lane divided and three- and five-lane roads with center TWLTLs in urban and suburban areas. Chapter 12 also includes three- and four-leg intersections with minor-road stop control or traffic signal control on all of the roadway cross sections to which the chapter applies. • NCHRP Report 839: A Performance-Based Highway Geometric Design Process (Neuman et al. 2017). The research on which this report is based assesses the existing geometric design process and presents suggested changes to ensure that recent advances in knowledge and emerging issues are incorporated in the design process. The report proposes that the end goal of all geometric design needs to be measured in the metrics of transportation perfor- mance, including mobility, accessibility, safety, maintenance and operations, and state-of- good-repair. Every phase, methodology or model developed and applied to conducting the highway design and to establishing the highway design criteria should be objectively related to one or more measures of transportation performance. The revised geometric design process recommended by NCHRP Report 839 provides guide- lines based on the project type and the problem or need being addressed. As noted in the report summary, “The geometric design criteria for any given project is recommended to be based on the context of the project location, and not limited to the facility type. This revised highway design process is intended for further development to become fully implementable” (Neuman et al. 2017). The report further acknowledges that the geometric design process, historically focused solely on motorized vehicles, must evolve to more directly and routinely address the needs of all potential users of a facility or corridor. Process and cultural change within the road design community are needed. Prioritizing the amount and manner of transportation service afforded general-purpose traffic, transit, truck and freight traffic, bicyclists and pedestrians involves inherent conflicts and choices. A design process that directs the resolution of such conflicts can establish a balance of choices among all needs. NCHRP Report 839 suggests more refined context definitions to identify corridors and conditions in which, for example, pedestrian needs should take precedence over motorized vehicles (e.g., to ensure that pedestrian facilities comply with ADA requirements). The pre- sumptive need to design cross sections, intersections and vertical alignment recognizing the presence of bicycles is similarly desirable. • TCRP Report 165: Transit Capacity and Quality of Service Manual, 3d Ed. (TCQSM 3d Ed.) (Kittelson and Associates, Inc., et al. 2013). The TCQSM 3d Ed. focuses on the evaluation of transit facilities, whereas the HCM considers the effects of transit presence along urban streets within its multimodal analysis framework. As a reference document, the TCQSM 3d Ed. func- tions as a companion to the HCM that provides current research-based guidance on transit capacity and QOS issues and the factors influencing both. The manual contains background, statistics and graphics on the various types of public transporta- tion, and it provides a framework for measuring transit availability, comfort, and convenience from the passenger and transit provider points of view. The manual contains quantitative techniques for cal- culating the capacity and other operational characteristics of bus, rail, demand-responsive, and ferry transit services, as well as transit stops, stations, and terminals. Example calculations are included. The TCQSM and the accompanying CD-ROM are intended for use by a range of practitioners, including transit planners, transportation planners, traffic engineers, transit operations personnel, design engi- neers, management personnel, teachers, and university students. • NCHRP Report 785: Performance-Based Analysis of Geometric Design of Highways and Streets (Ray et al. 2014). This report presents an approach for understanding the desired outcomes of a project, selecting performance measures that align with those outcomes, evalu- ating the impact of alternative geometric design decisions on those performance measures, and arriving at solutions that achieve the overall desired project outcomes. For both new

48 Design Guide for Low-Speed Multimodal Roadways construction and reconstruction of highways and streets, stakeholders and decision makers increasingly want reasonable measures of the effect of geometric design decisions on the facil- ity’s performance for all of its users. The report includes information that helps a designer develop the foundation for performance-based analysis to inform geometric design decisions, followed by applications guidance to incorporate performance-based analysis into project development and geometric design decisions. The report correctly notes that the expected performance of the facility is only one of the factors that must be considered in designing a highway or street, and a better understanding of the expected performance should result in better decisions during the design process. • Applying Performance Based Practical Design Methods to Complete Streets—A Primer on Employing Performance-Based Practical Design and Transportation Systems Management and Operations to Enhance the Design of Complete Streets (FHWA 2016b). This primer addresses performance-based “practical design” (PBPD) approaches for roadways being designed to serve all users, recognizing that urban and suburban streets must serve many types of users and trips in right-of-way that is often constrained. It discusses use of design principles that seek to better share the limited street right-of-way among multiple users while enhancing the livability of the street for adjacent residents. The primer describes how PBPD modifies the traditional “top-down, standards-first” approach to a “design up” approach in which designers and decision makers exercise engineering judgment to build up the roadway and operational improvements from existing conditions to meet both project and system objectives. The primer also describes how PBPD uses appropriate analysis tools to evaluate the perfor- mance impacts of planning and design decisions in relation to the cost of providing various geometric elements and operational features. The primer notes that for lower-volume and lower-speed streets (defined as under 20,000 average annual daily traffic [AADT] and under 35 mph), many of the design trade-offs (e.g., narrow lanes, reduced lanes, adding bike lanes) are easy to make, requiring little formal trade-off analysis. The larger challenge exists with retrofitting for improved pedestrian, bicycle and transit accessibility on a higher volume or higher speed street where a more formal trade-off analysis using the PBPD process should be used. • Evaluating Complete Streets Projects: A Guide for Practitioners (AARP and the National Complete Streets Coalition 2015). This guidebook provides a range of measures and metrics for project evaluation. The guidebook notes common project goals, which include: providing access to destinations, supporting the local economy, ensuring environmental quality, provid- ing vital public places and improving safety for all travelers. Additionally, many communities focus on the goals of improving public health and addressing equity, both of which have measures cut across other goals. For each goal, the guidebook provides potential “complete streets” measures and ways to quantify each measure that can be used before and after completion of a specific project. The following measures and metrics are addressed for project level evaluation (AARP and the National Complete Streets Coalition 2015): – Access; – Economy; – Environment; – Place; – Safety; – Equity; and – Public health. • Guide to Sustainable Transportation Performance Measures (U.S. EPA 2011). This guide- book identifies ten performance measures that can readily be developed and applied in transportation decision making. For each measure, the EPA guide presents possible

Balancing User Performance in Low- and Intermediate-Speed Environments 49 metrics, summarizes the relevant analytical methods and data sources, and illustrates the use of each measure by one or more transportation agencies. The ten profiled measures are: 1. Transit accessibility, 2. Bicycle and pedestrian mode share, 3. VMT per capita, 4. Carbon intensity, 5. Mixed land uses, 6. Transportation affordability, 7. Distribution of benefits by income group, 8. Land consumption, 9. Bicycle and pedestrian activity and safety, and 10. Bicycle and pedestrian LOS. 3.2.4 Selecting Performance Measure, LOS and QOS Tools The documents reviewed in the preceding section and those listed in Exhibit 3-3 provide tools that can assist the designer in assessing performance, LOS and QOS for the full range of users and modes in the design of road and street facilities in low- and intermediate-speed ranges. Although these publications differ widely in the scale and complexity of their approaches, the resource documents listed in Exhibit 3-3 also are potentially valuable resources that can support the design practitioner in evaluating and making design choices for multimodal design. The methods and tools addressed range from data-intensive quantitative analy- sis to low-data qualitative approaches and tools that combine quantitative and qualitative methods. 3.3 Design Volumes and Design Years Transportation demands, including volume of users, composition of users and patterns of users, are all important design controls. Conventional geometric design processes have typically focused only on current and future projections of vehicle and truck demand. Where projects will serve non-motorized users in addition to vehicular traffic, however, it is impor- tant to obtain and understand similar demand data and patterns for transit vehicles and riders, pedestrians and bicyclists to perform multimodal design effectively. The designer must have a good understanding of both existing and anticipated demands to size, locate and integrate transit, bicycle and pedestrian facilities into the overall project design. Com- munity planning and corridor goals, the selected design year, and other identified project performance measures also are key determinants of how the design will achieve the project’s purpose and serve all users. 3.3.1 Selecting a Project Design Year Normally, project designs accommodate travel demands likely to occur within the life of the facility under reasonable maintenance. This usually involves projecting future conditions for a selected planning horizon year. Projections of future demand for larger transportation proj- ects usually are made for a range of 15 to 30 years. For large projects, agencies often will select 20 years from the expected facility completion date as the design year. Many agencies consider this a reasonable compromise between a facility’s useful life, the uncertainties of long-range projections, and the consequences of inaccurate projections. For smaller, lower-cost projects, agencies will often use a planning horizon of 5 to 10 years.

50 Design Guide for Low-Speed Multimodal Roadways Resource Document User Facilities Combined (All Users) Vehicles Pedestrians Bicycles Shared- Use Path Transit Guidebook for Developing Pedestrian and Bicycle Performance Measures (FHWA 2016c) X X HCM 6th Ed. (TRB 2016b) X X X X X X HSM (AASHTO 2010) * X X X X NCHRP Report 825 (Dowling et al. 2016) X X X X X X NCHRP Report 839 (Neuman et al. 2017) X X X X X X Analysis Procedures Manual (APM) (Oregon DOT 2016), Chapter 14: Multimodal Analysis X X X X X X Evaluating Complete Streets Projects: A Guide for Practitioners (AARP and the National Complete Streets Coalition 2015) X X X X X X TCQSM 3d Ed. (Kittelson and Associates, Inc., et al. 2013) X Quality/Level of Service Handbook (Florida DOT 2013) X X X X X X Low-Stress Bicycling and Network Connectivity, MTI Report 11-19 (MTI 2012) X “Multimodal Level of Service in King County: A Guide to Incorporating All Modes of Transportation into Local Jurisdictions’ Roadway Performance Measurements,” slide presentation (Cascade Bicycle Club 2011) X X X X X X “HPE’s Walkability Index: Quantifying the Pedestrian Experience” in the Compendium of Technical Papers, ITE 2010 Technical Conference and Exhibit, Savannah, GA (ITE 2010b) X Flagstaff Pathways 2030 Regional Transportation Plan (Flagstaff MPO 2009), Level of Service Guidelines for Pedestrian, Bicycle and Transit Facilities X X X Bicycle Environmental Quality Index (BEQI): Draft Report (SFDPH 2009), Pedestrian and Bicycle Environmental Quality Indices X X Multimodal LOS Standards for Signalized Intersections (City of Charlotte, NC 2007a) X X X X X Evaluation of Safety, Design, and Operation of Shared-Use Paths - Final Report, FHWA-HRT-05- 137 (FHWA 2006a) X X X Multimodal Transportation Level of Service Manual (City of Fort Collins, CO 1997) X X X X X Multimodal Level of Service Toolkit (Fehr and Peers n.d.) X X X X X Bicycle Level of Service: Applied Model (Sprinkle Consulting, Inc. 2007a) X Pedestrian Level-of-Service Model (Sprinkle Consulting, Inc. 2007b) X * With 2014 supplements Exhibit 3-3. Resources for assessing multimodal performance measures, LOS and QOS.

Balancing User Performance in Low- and Intermediate-Speed Environments 51 3.3.2 Projecting Future Multimodal Demand Forecasts of future user demand should reflect community and regional plans, changes in proj- ect context over the analysis period, and the project’s purpose and need. Based on these consider- ations, a future conditions projection represents a technical analysis and policy consensus on the type and developed intensity of land use, future local and regional economic activity, presence of transit service, changes in transit service, the anticipated presence and needs of pedestrians and bicyclists, and other possible factors. Forecasts of future user activity levels should include estimates of pedestrian and bicycle activ- ity as well as transit vehicles and other motorized vehicles. Particular care must be taken when forecasting pedestrian and bicycle volumes. Latent potential demand above observed pedestrian and bicycle volumes in the project area may exist if no adequate facilities exist for those users, if existing facilities are substandard in some way, or if they do not provide complete connectiv- ity to existing or planned destinations. It is also important to evaluate future land use context and development, including any potential attractors such as new transit service lines or stops, schools, parks, office and retail uses that may be located near existing or planned residential development. In many communities, computer-based transportation demand models, typically developed at the regional level, are used as the basis for vehicle traffic projections. Typically, the computer model is calibrated to emulate existing and future transportation demands based on current and future projections of land use growth (population, economy and employment), planned transportation investments and estimated percent of non-vehicular travel (e.g., transit trips and, in some regions, bicycle trips). If transportation demand models are not available or not used to project future traffic, many agencies will apply an average annual growth percentage—often in the range of 1 to 2 percent—to estimate future design year project volumes. When applied over a 20-year or 30-year period, the annual growth percentage will result in significant traffic growth. For example, a 2 percent traffic growth rate applied over 35 years will approximately double the amount of traffic compared to the traffic in place today. The typical process for forecasting user volumes assumes that traffic will increase over time, at many locations; however, buildout or near buildout of land use will have occurred already, and user volumes may remain relatively constant or even decline over time. Individual projects should be assessed on a case-by-case basis to analyze how standard traffic growth factors (land use trip generation, ambient growth) may support or conflict with the cor- ridor and community plans. Future analysis should typically begin with the vision for the future function of the road, including the roadside and land use context, so that design treatments can support and complement these goals. Some communities intentionally constrain roadways to inhibit growth when their overall vision for the roadway is considered more important than the roadway’s vehicle traffic-carrying capacity. Ideally, in multimodal environments, community planners and roadway designers work together to determine the appropriate estimates of future modal activity levels to use as a foun- dation for the design process. For the typical project undertaken within a community (e.g., an intersection or corridor improvement project), the user demand forecast is based on existing conditions. 3.3.3 Pedestrian Demands Pedestrian counts are completed to determine pedestrian flows, patterns and peak hours. The pedestrian counts should include sidewalk demands, crossing demands, and storage demands at corners, traffic islands and medians (i.e., total number of pedestrians waiting to cross the street).

52 Design Guide for Low-Speed Multimodal Roadways Seasonal adjustments to the counts may be needed to ensure the count data accurately represents the average annual conditions. Finally, future design year conditions are estimated by adding to or subtracting from the existing traffic volumes to account for any network changes, future projects and future changes in localized development and context. In addition to pedestrian counts, the project area should be evaluated to determine if latent potential demand for pedestrian accommodation exists because of an uncomfortable existing walking environment, missing links in the pedestrian network or expected changes in develop- ment patterns. The likelihood of latent demand can be assessed by looking at surrounding land uses and their propensity to generate pedestrian activity. Designers also can look for conditions like pathways worn along the roadside to determine if pedestrian connectivity is underserved. It may be important to complete pedestrian counts for other times of the day (beyond the typical morning and evening peak hours) and/or on weekends, depending on the project area. For example, observing pedestrian flows during morning and mid-afternoon periods will be important for a project area that is heavily influenced by a school. Public assembly facilities and transit stops or stations also merit special consideration because they can produce high volumes of pedestrians over short durations. To determine the appropriate locations for pedestrian counts (including project-area inter- sections), it is important to review current pedestrian routes between activity centers. Infor- mal paths or crossing locations may warrant supplemental pedestrian observations during project planning. 3.3.4 Bicycle Demands Bicycle demands should be counted during peak hours concurrent with vehicle intersection turning movement counts. As with pedestrian activity, the designer should evaluate the proj- ect area to determine if potential latent demand exists for bicycle accommodation. Additional consideration of bicycle demands during other periods of the day and/or on weekends may warrant supplemental counts. Methods for forecasting bicycle demand are still evolving through national transportation research. Common practices to gauge future demands currently include sampling demand at similar settings or facilities and evaluating surrounding land uses for their propensity to generate bicycle activity. 3.3.5 Motorized-Vehicle Demands Daily traffic, peak-hour traffic, and traffic patterns of motorized vehicles are needed as input to the design of street and roadway facilities. The following vehicle measure projections are developed for a typical roadway design project: • AADT: The total yearly volume of automobiles and trucks divided by the number of days in the year; • Average daily traffic (ADT): The calculation of average traffic volumes in a time period greater than one day and less than one year; • Peak-hour traffic (PH): The highest number of vehicles passing over a section of roadway during 60 consecutive minutes, with T(PH) used to indicate the PH for truck traffic only; • Peak-hour factor (PHF): A ratio of the total volume occurring during the peak hour to the maximum rate of flow during a given time period within the peak hour (typically is 15 minutes); • Design hourly volume (DHV): The 1-hour volume in the design year selected for determin- ing the geometric requirements of the roadway design (often the typical worst-case weekday morning or evening peak hour or the 30th-highest hour of the year); and • K-factor (K): The percent of daily traffic that occurs during the peak hour.

Balancing User Performance in Low- and Intermediate-Speed Environments 53 Planning and design of transportation projects will generally need turning movement counts (TMCs) at intersections, including heavy vehicle movements and automatic traffic recorder (ATR) vehicle classification counts along roadways. These counts can be used to provide esti- mates of the values for the listed projections. Where pedestrian and bicycle activity are present, the counts should include them, and all counts should be performed in fair weather. The DHV (or the daily peak hours) influence design elements, such as the desired number of travel lanes, lane and shoulder width, and intersection layouts. The DHV also may influence the LOS provided and the accommodation appropriate for pedestrians and bicyclists. The selected DHV has a significant impact on the characteristics of a project. Designers should ensure that the selected DHV effectively matches the facility to the traffic volumes it will carry on a regular basis so that the project is not “over-designed.” For example, accommodating a high volume that is expected to occur infrequently may result in a costly project that has significant adverse impacts. Likewise, accommodating a lower design volume that frequently is exceeded may result in significant congestion and not meet the LOS expectations for various users. Large or heavy vehicles, such as trucks and buses, have different operating characteristics from passenger cars and bicycles, and these characteristics can affect traffic operations. In planning and design, the number of trucks and buses expected to use a facility needs to be estimated for both daily and peak-hour conditions. For highway capacity purposes, heavy vehicles typically are defined as all buses, single-unit trucks, and truck combinations other than light delivery trucks. 3.4 Recommended Minimum Multimodal Accommodation Agencies and designers often ask, “What is a reasonable minimum accommodation for all users?” To serve motorized vehicles on a low-volume and low-speed two-way street, the mini- mum is one travel lane in each direction with a minimum lane width of 9 to 10 ft. As volumes and speeds increase, the number and width of lanes also increase as needed for vehicle mobility and safety purposes. In the case of pedestrians, the minimum accommodation can range from (1) no facilities in rural contexts with no (or rare) demand, to (2) traveled way shoulders in rural settings with infrequent levels of pedestrian activity, and (3) paved sidewalks of 5 ft. and wider in rural town, suburban, urban and urban core contexts. In the case of bicyclists, the mini- mum accommodation on low-volume, low-speed roadways may be shared use of vehicle lanes. As volumes increase in suburban and urban contexts, the minimum accommodation may be determined to be striped bicycle lanes, separated bicycle tracks and even off-street paths located in the roadway border area. Transit accommodation also can vary widely based on the type and frequency of transit service and ridership. For many years, the HCM has assisted designers in determining the minimum traveled way design to provide a desired LOS for motorized vehicles. Many factors, including functional clas- sification, design volumes, design vehicles, design speed and other criteria, have led designers to develop acceptable project designs meeting desired performance measures using geomet- ric design guidance such as the AASHTO Green Book and supporting publications. During this same period, however, generally little definitive guidance has been available on minimum accommodation for non-motorized or transit modes that may be legally using the right-of-way. Many past project designs either have not provided reasonable accommodation for pedestrian, bicycle and transit users or have provided such accommodation as an afterthought, resulting in poor service and quality levels. Considerable discussion, along with some debate, has been devoted to what type and level of accommodation constitutes a “minimum” reasonable accommodation for pedestrians, bicyclists

54 Design Guide for Low-Speed Multimodal Roadways and transit access in the street and roadway system. As pedestrian and bicycle travel have increased over time (along with related crash and fatality rates), more state, local and federal agencies have placed new or expanded focus on providing more and better facilities for these users in the right-of-way, even though their numbers are small compared to motorized user volumes. This multimodal focus also reflects increased efforts to create more vibrant and livable communities and neighborhoods that support a healthier lifestyle and support a community’s economic goals. With those goals and benefits in mind, the minimum accommodation shown in Exhibit 3-4 is suggested for low- and intermediate-speed streets and roads where non-motorized users are allowed to use the right-of-way by law. The needs of all legal users of the right-of-way, including pedestrians, bicyclists and transit users, should be considered in the design of a roadway project unless a user mode is specifically prohibited on that facility by law. FHWA provides comprehensive guidance for the provision of reasonable facilities to accommodate these transportation system users without the appli- cation of detailed multimodal analysis in the Pedestrian Safety Guide and Countermeasure Selection System and the Bicycle Safety Guide and Countermeasure Selection System on its PedBikeSafe website (FHWA n.d.d). Another source of information is the PROWAG (U.S. Access Board 2011). Constraints and possible exceptions to these minimum recommended accommodations will always exist because of several possible factors that could affect a given project; in general, how- ever, the ability for all legal users to access and conveniently use a roadway right-of-way in a safe and reasonable manner should be provided regardless of the level of their activity. Pedestrians, bicyclists and transit users almost always will constitute lower volumes than motorized vehicles except in some urban core contexts, but their opportunity to use the roadway right-of-way is no less important than that of drivers. Context User Motorized vehicles Pedestrians Bicycles Transit Rural Minimum number of travel lanes determined by functional classification, transportation plans and selected performance measures, balanced with other modal needs within the right-of- way. Minimum 4-ft. paved or stabilized shoulders on both sides of road unless volumes and speeds are low.* Separate paved sidewalks/paths not normally required unless nearby pedestrian generators exist. Determined by existing and planned bicycle usage. May range from no facilities, to use of roadway shoulder (min. 4 ft.), to on- street striped bicycle lanes, to separated cycle tracks, to roadside bicycle or shared-use paths. State, regional and local bicycle and transportation plans should be consulted. Traveled way transit facilities determined by selected performance measures. Minimum 5-ft. paved accessible sidewalks or path from nearby pedestrian generators to transit stops. Additional transit stop facilities as needed for demand. Minimum 5-ft. paved accessible sidewalks or pathways along both sides of roadway unless volumes and speeds are low. * Suburban Minimum 5-ft. paved accessible sidewalks or path along both sides of roadway unless volumes and speeds are low.* Urban Minimum 5-ft. paved accessible sidewalks or path along both sides of roadway. Urban Core Minimum 5-ft. paved accessible sidewalks or path along both sides of roadway. * ADT = 2,000 vehicles per day or less, 85th percentile speeds 30 mph or lower Rural Town Exhibit 3-4. Minimum recommended low- and intermediate-speed roadway user accommodation by context zone.

Balancing User Performance in Low- and Intermediate-Speed Environments 55 Exceptions to meeting the minimum accommodations follow the FHWA guidance on accom- modating bicycle and pedestrian travel and identified best practices for providing multimodal accommodation. Accommodation is not necessary in the following cases: • Prohibited use. This exception involves corridors where specific users are prohibited by law (e.g., Interstate highways/freeways, expressways or pedestrian malls. • No observed or planned need. This exception involves a documented absence, or extremely infrequent expectation, of current and future need for a particular mode. • Cost. This exception occurs when the cost to provide accommodation for one or more modes is excessively disproportionate to the need or probable use. Determining a percentage cost to define “excessive” is difficult, as the context for many projects requires different portions of the overall project budget to be spent on the modes and users expected; additionally, the costs often may be difficult to quantify. A percentage cap may be appropriate in unusual cir- cumstances, such as where natural features (e.g., steep hillsides, shorelines) or environmental constraints make it very costly or even impossible to accommodate all modes. If an identified percentage increase cap exists, it should normally be used in an advisory sense rather than absolute sense. • Alternate accommodation. This exception occurs when a reasonable and equivalent accom- modation project along the same route or corridor is already programmed to provide reason- able replacement facilities for those exempted from the project being designed. 3.5 Relationships between Geometric Design and Performance of All Users NCHRP Report 785 (Ray et al. 2014) provides performance-based guidance in four key areas: • Selecting the desired outcomes of a project; • Selecting performance measures that help to achieve those outcomes; • Evaluating how various alternative geometric design decisions may impact those measures; and • Selecting preferred design solutions that help to achieve the overall desired project outcomes. The first part of NCHRP Report 785 presents the body of knowledge that forms the founda- tion for performance-based analysis to inform geometric design decisions, and the second part provides applications guidance to incorporate performance-based analysis into project develop- ment and geometric design decisions. Geometric design decisions for roadways and streets act individually and together to impact project performance in ways that may or may not be consistent with broader community goals not related to vehicle traffic flow. NCHRP Report 785 guides the user in conducting performance- based analysis and can assist geometric designers in better understanding the most critical trans- portation performance areas and how they relate to geometric design elements. NCHRP Report 785 identifies and defines five key transportation performance categories. Although the designer should consult the full report for specific guidance on how to incorporate performance-based analysis into the design of their projects, the following points highlight key parts of the report’s discussion of relationship between key categories of roadway facility perfor- mance and individual geometric design elements: • Access and accessibility. The report defines accessibility as “the ability to approach a desired destination or potential opportunity for activity” using roads and streets, including the side- walks and/or bicycle lanes provided within those rights-of-way. It notes that these perfor- mance measures have not traditionally been considered during geometric design stages of

56 Design Guide for Low-Speed Multimodal Roadways project development, and that they “tend to require performance prediction tools that are typically not used by designers.” The report uses these measures to quantify accessibility: driveway density, transit stop spacing, and presence of pedestrian and/or bicycle facilities. • Mobility. NCHRP Report 785 defines mobility as “the ability to move various users efficiently from one place to another using roadways and streets” and identifies performance mea- sures for mobility that are sensitive to geometric design, including “speed and measures that involve speed (e.g., delay, travel time).” Significantly, the report notes that “these measures can be equally applied to any travel mode; however, non-motorized movement performance may be more meaningfully quantified using measures of accessibility and quality of service.” • QOS. Defining QOS as “the perceived quality of travel by a road user,” the report notes that QOS is used in the HCM “to assess multimodal level of service (MMLOS) for motorists, pedes- trians, bicyclists, and transit users.” Measures of quality include “average travel speed, control delay, density, percent time-spent-following, driveway density, separation between motorized and non-motorized modes, amount of space provided for pedestrians and bicyclists, frequency of transit service, transit service amenities, and frequency of opportunities for pedestrians to cross a street.” QOS also may include “the perceived quality of travel by design vehicle users such as truck or bus drivers,” and “users’ perceptions of safety.” • Reliability. Defined as “the consistency of performance over a series of time periods (e.g., hour-to-hour, day-to-day, year-to-year),” transportation service reliability “is commonly linked to travel-time variability, but the basic concept applies to any other travel-time-based metric (e.g., average speed, delay).” The report also notes that geometric design may affect a roadway’s ability “to ‘absorb’ random, additional traffic demand as well as capacity reductions due to incidents (e.g., crashes, vehicle breakdowns), weather, and maintenance operations, among others. Reliability also is indirectly related to geometry inasmuch as the geometry affects the frequency and severity of random events that impact travel time (e.g., crashes).” • Safety. NCHRP Report 785 defines safety as “the expected frequency and severity of crashes occur- ring on highways and streets,” adding that “[e]xpected crash frequencies are often disaggregated by level of crash severity and crash type, including whether or not a crash involves a non-motorized user or a specific vehicle type (e.g., heavy vehicle, transit vehicle, motorcycle). Measures that com- bine crash frequencies and severities into a common unit (e.g., crash cost, equivalent property damage only, relative severity index) are sometimes used when comparing design alternatives.” 3.5.1 Relationships Between Geometric Design Elements and Performance Categories The design guidance in NCHRP Report 785 is based on research findings from several publica- tions and documents, including the HSM, HCM, and TCQSM 2d ed.; FHWA’s Speed Concepts: Informational Guide (FHWA 2009c); the Interactive Highway Safety Design Model (IHSDM) (FHWA 2003); draft HSM chapters for freeways and interchanges developed in the contrac- tor’s final report for NCHRP Project 17-45, “Safety Prediction Methodology and Analysis Tool for Freeways and Interchanges” (TTI and CH2M-Hill 2012); and several additional tools that address relationships between geometric design and performance. The information presented in NCHRP Report 785 focuses on what are considered to be high-priority, well-established and direct relationships between geometric design decisions and performance. It stresses that practitioners should also be aware of the broader range of expected relationships, because limitations in data, analysis techniques, and other similar chal- lenges suggest that likely relationships exist that have not yet been clearly defined, quantified and documented. The report also provides some information on “expected” or “likely” relationships between performance and geometric elements that, as of its publication, had not yet been addressed in

Balancing User Performance in Low- and Intermediate-Speed Environments 57 published research findings. Exhibits 3-5 and 3-6 address expected relationships for roadway segments and intersections. Both tables include information on pedestrian and bicycle design facilities and other design elements that potentially affect the performance outcomes of those modes (e.g., roadside design features, bridge cross section, travel lane widths, median provisions, traffic islands and shoulder type/width). NCHRP Report 785 develops and uses three possible notations to classify each geometric char- acteristic or design decision and performance category combination as either “expected direct effect,” “expected indirect effect,” or “no expected effect”: The notations are defined as follows: Source: Exhibit 4-3 in NCHRP Report 785 (Ray et al. 2014) Exhibit 3-5. Segments: expected geometric elements and performance relationships.

58 Design Guide for Low-Speed Multimodal Roadways • “Expected direct effects” are performance effects caused by the geometric design decisions that occur at the same time and place (e.g., a given horizontal curve radius will immediately affect expected crash frequency at the curve location); • “Expected indirect effects” are performance effects caused by the geometric design decision but occur either later in time (e.g., providing additional auto capacity induces more auto travel) or farther removed in distance (e.g., growth-inducing effects and other effects related to changes in the pattern of land use and traffic patterns induced by the geometric choice); • “No expected effect” indicates a geometric characteristic or design decision that is expected to have no direct or indirect impact on the aspect of performance being assessed. Exhibits 3-5 and 3-6 also include notations that indicate whether the expected relationship has been addressed in research and is included as part of a performance prediction tool, an accepted publication, or another knowledge source. 3.5.2 Performance Categories and Performance Measures NCHRP Report 785 presents information about design elements and decisions related to segments and intersections, and their relationship to performance measures from each of five Source: Exhibit 4-4 in NCHRP Report 785 (Ray et al. 2014) Exhibit 3-6. Intersections: expected geometric elements and performance relationships.

Balancing User Performance in Low- and Intermediate-Speed Environments 59 previously defined transportation performance categories: (1) accessibility, (2) mobility, (3) QOS, (4) reliability and (5) safety. This section summarizes, by facility type, the performance measures specific to the five performance categories. 3.5.2.1 Accessibility Accessibility is defined as the ability to approach a desired destination or potential opportu- nity for activity using highways and streets (including sidewalks and/or bicycle lanes). Exhibit 3-7 summarizes, by facility type, the performance measures specific to access and accessibility, the sensitive geometric design elements that influence those performance mea- sures, the basic relationship between the design elements and the performance measures and potential trade-offs between the design element and the performance of other transportation elements. The exhibit also lists resources useful for evaluating the sensitivity of the geometric relationships in detail. 3.5.2.2 Mobility Mobility is defined as the ability to move various users efficiently from one place to another using highways and streets. Exhibit 3-8 summarizes, by facility type, the performance measures specific to mobility, the sensitive geometric design elements influencing those performance mea- sures, the basic relationship between the design element and the performance measure, and potential trade-offs between the design element and the performance of other transportation elements. The table also lists resources that can be used to evaluate the sensitivity of that geometric rela- tionship in detail. NCHRP Report 785 notes specifically that improving many mobility-oriented Facility Type Performance Measure Definition Geometric Design Elements Basic Relationship Potential Performance Trade-offs Evaluation Resources Segment Driveway density Number of driveways per mile Access points and density Higher density of driveways associated with higher motor vehicle access Degrades bicycle LOS, increases crash likelihood, increases average travel speed HCM 2010 Chapters 16 and 17; HSM Part C Urban/ Suburban Segment Transit stop spacing Distance between transit stops along a roadway segment Transit accommodation features Higher frequency increases access for transit riders Increases transit travel time and may degrade mobility for other vehicle modes TCQSM Segment Presence of pedestrian facility Presence of a sidewalk, multiuse path, or shoulder Sidewalk and pedestrian facilities Greater connectivity and continuity of pedestrian network increase access for pedestrians Implementing pedestrian facilities in a constrained environment may require removing capacity or parking for vehicle mode HCM 2010 Chapters 16 and 17 Segment Presence of bicycle facility Presence of bicycle lanes, multiuse path, or shoulder Bicycle accommodation features Greater connectivity and continuity of bicycle network increase access for bicyclists Implementing bicycle facilities in a constrained environment may require removing capacity or parking for vehicle mode HCM 2010 Chapters 16 and 17 Source: From Exhibit 4-6 in NCHRP Report 785 (Ray et al. 2014) Exhibit 3-7. Access and accessibility performance measures.

60 Design Guide for Low-Speed Multimodal Roadways * FHWA Speed Concepts: Informational Guide (Donnell et al. 2009) ** NCHRP Report 687 (Ray et al. 2011) *** NCHRP Report 672 (Rodegerdts et al. 2010) Source: From Exhibit 4-7 in NCHRP Report 785 (Ray et al. 2014) Facility Type Performance Measure Definition Evaluation Resources Increased vehicle lanes decrease average travel time for autos and increases vehicle speed Degrades quality of service for pedestrians and bicyclists Degrades mobility for pedestrians and bicyclists HCM 2010 Chapter 10, Freeway Facilities, Chapter 14 Multilane Highways Geometric Design Elements Basic Relationship Potential Performance Trade-offs The mean amount of time it takes a road user to travel from one point to another point along a roadway segment Number of travel lanes Average travel time Segment Higher inferred speeds associated with higher free-flow speeds and higher mobility Higher vehicle speeds are also associated with higher severity crashes FHWA Speed Concepts: Informational Guide* The maximum speed for which all critical design- speed-related criteria are met at a particular location Horizontal alignment, vertical alignment, and cross section Inferred speed Segment Increased opportunities to pass slow- moving vehicles reduces percent time spent following, providing a passing lane can reduce crashes Increases vehicle speeds, increases potential for higher severity crashes HSM Chapter 10; HCM 2010 Chapter 15 The average percentage of total travel time that vehicles must travel in platoons behind slower vehicles due to an inability to pass Horizontal and vertical alignment, sight distance, type and location of auxiliary lanes Average percent time spent following Two-Lane Segment At relatively high exit ramp volumes, ramp spacing affects freeway speeds Decreased freeway speeds are possible with decreased ramp spacing An auxiliary lane may improve freeway speeds NCHRP Report 687 **; HCM 2010 Chapters 11, 12 and 13 The freeway speed down- stream of an entrance ramp and before an exit ramp or another entrance ramp Ramp spacing dimensions as defined in NCHRP Report 687 Use of downstream auxiliary lane Freeway speed Freeway Segment Lower control delay for any road user improves mobility for that mode Often trade-offs occur between delay experienced by different modes depending on the type of traffic control present HCM 2010 Chapters 18 through 22; NCHRP Report 672 *** Average control delay experienced by road users at an intersection Intersection form, control type, and features; number and types of lanes DelayIntersection Increased vehicle capacity associated with lower v/c ratios Degrades quality of service for pedestrians and bicyclists Degrades mobility for pedestrians and bicyclists HCM 2010 Chapters 18 through 22; NCHRP Report 672 The ratio of volume present or forecasted and the available capacity at the intersection Intersection form, control type, and features; number and types of lanes Volume-to- capacity (v/c) ratio Intersection Exhibit 3-8. Mobility performance measures.

Balancing User Performance in Low- and Intermediate-Speed Environments 61 performance measures for vehicles can potentially negatively affect the QOS for pedestrians, bicyclists, or transit users. The trade-off that often occurs in providing additional vehicle capac- ity is increased speeds of motorized vehicles. Increased speeds are associated with lower QOS (e.g., lower comfort and safety) for pedestrian, bicycle, and transit modes. Additional vehicle capacity also can come at the expense of providing pedestrian or bicycle facilities. In some cases, however, providing a bicycle lane can provide a de facto shoulder or a shoulder can serve as a de facto bicycle lane. 3.5.2.3 QOS QOS is defined as the perceived quality of travel by a road user. In the HCM 2010, QOS is used to assess LOS simultaneously for motorists, pedestrians, bicyclists, and transit riders (i.e., MMLOS). It may also include the perceived quality of travel by users of larger vehicles such as trucks or transit vehicles. The QOS metrics summarized in Exhibit 3-9 represent a combination of recent advancements in how the transportation profession understands, evaluates and attempts to quantify quality of travel experience for different road users and fundamental considerations related to critical design vehicles that need to be served within a project. Research on multimodal QOS, especially that related to pedestrian and bicycle QOS, will likely continue to evolve as practitioners increase their focus and attention on creating (or retrofitting existing roadways to create) “complete streets” that better serve a wide range of road users. Exhibit 3-9 summarizes, by facility type, the performance measures specific to QOS, the sensitive geometric design elements influencing those performance measures, the basic rela- tionship between the design element and the performance measure, and potential trade-offs between the design element and the performance of other transportation elements. The table also lists resources that can be used to evaluate the sensitivity of that geometric relationship in detail. 3.5.2.4 Reliability Research continues in the transportation profession to develop performance measures that can connect reliability to specific geometric design elements or decisions, but at publication of NCHRP Report 785 the authors noted that no clear set of measures was yet available to use in making design decisions. The authors observed that two performance measures (variation in travel time and variation in speed) were used to understand potential reliability of a facility for the vehicle mode, and that several design considerations could be applied to roadways and streets, including trade-offs between implementing transit signal priority, bus-only lanes, and/ or queue jumps for transit vehicles along an urban corridor to improve the reliability of bus service with the potential impact of degrading mobility for side street vehicle traffic. No men- tion is made in the report of how providing reliability may be related to elements of design for pedestrians and bicycles. 3.5.2.5 Safety Safety is defined as the frequency and severity of crashes occurring on or expected to occur on roadways or streets. Exhibit 3-10 summarizes, by facility type, the performance measures specific to safety, the sensitive geometric design elements that influence those performance measures, the basic relationship between the design element and the performance measure, and resources or tools that can be used to evaluate the sensitivity of that geometric relationship in detail. NCHRP Report 785 also notes other resources that may be beneficial in consider- ing safety performance, including FHWA’s Crash Modification Factor Clearinghouse webpage (CMF Clearinghouse n.d.).

62 Design Guide for Low-Speed Multimodal Roadways Facility Type Performance Measure Definition Geometric Design Elements Basic Relationship Potential Performance Trade-offs Evaluation Resources Urban/ Suburban Segment Pedestrian LOS A letter grade associated with the quality of travel experience for a pedestrian; based on HCM 2010 methodology Sidewalk and pedestrian facilities, width of pedestrian lanes, buffer from vehicle traffic, driveway density, crossing frequency Increasing width of pedestrian facility, increasing distance from vehicle traffic, decreasing driveway density, and increasing opportunities to cross a street improve pedestrian LOS Meeting performance metrics for pedestrians may degrade travel quality for other modes – e.g., on-street parking improves pedestrian LOS and degrades BLOS HCM 2010 Chapters 16 and 17 Urban/ Suburban Intersections Pedestrian LOS A letter grade associated with the quality of travel experience for a pedestrian; based on HCM 2010 methodology Crossing distance, traffic control delay Decreasing pedestrian crossing distance and delay to cross a street improves pedestrian LOS Meeting performance metrics for pedestrians may degrade travel quality for other modes HCM 2010 Chapters 16 and 17 Urban/ Suburban Segment BLOS A letter grade associated with the quality of travel experience for a bicyclist; based on HCM 2010 methodology Bicycle accommodation features, physical separation from motorized vehicle traffic, access points and density, on- street parking Increasing width of bicycle facility, decreasing driveway density, increasing separation from moving vehicle traffic, and removing on-street parking improve BLOS Meeting performance metrics for bicyclists may degrade travel quality for other modes HCM 2010 Chapters 16 and 17 Urban/ Suburban Intersections BLOS A letter grade associated with the quality of travel experience for a bicyclist; based on HCM 2010 methodology Traffic control, delay Decreased delay for bicyclists increases quality of travel experience Meeting performance metrics for bicyclists may degrade travel quality for other modes HCM 2010 Chapters 16 and 17 Urban/ Suburban Segments and Intersections Transit LOS A letter grade associated with the quality of travel experience for a transit rider; based on HCM 2010 methodology Transit accommodations/ facilities (presence of transit-only lane, bus pullout areas, bus merge/diverge lanes, bus queue jump lanes) Providing bus-only lane, queue jump lanes, merge/diverge lanes decreases bus travel time and improves transit rider quality of travel Incorporating transit-only features often comes at the expense of providing additional auto or bicycle capacity or treatment HCM 2010 Chapters 16 and 17 Urban/ Suburban Segments and Intersections Auto LOS Number and duration of stops along an urban/ suburban corridor Number of travel lanes; intersection form, control type, and features Reducing the no. of stops and duration of stops along a corridor improves auto LOS Increased vehicle lanes and speeds degrade pedestrian and bicycle MMLOS HCM 2010 Chapters 16 and 17 Intersections and Segments Large- vehicle turning and off-tracking character- istics Ability and ease with which large vehicles are able to physically move through an intersection or along a segment Curve radii, curb radii, lane width Generally larger curve radii, larger curb radii, and wider vehicle lanes enable easier navigation for larger vehicles Increasing curve radii, curb radii, and lane width often degrades pedestrian and bicycle MMLOS due to the longer crossing distances AutoTURN, Truck Turning Templates Source: Exhibit 4-8 in NCHRP Report 785 (Ray et al. 2014) Exhibit 3-9. QOS performance measures.

Balancing User Performance in Low- and Intermediate-Speed Environments 63 3.6 Multimodal Project Design Development Process Numerous approaches and processes exist for developing a street or roadway project design that effectively serves all users. Each transportation agency will normally have its own design process and procedures based on factors such as project cost, funding source, type of project (e.g., new construc- tion; reconstruction; and resurfacing, restoration and rehabilitation, often called “3R”) and other factors. Project design normally is guided by agency design manuals and standards, and may include “typical” sections or design solutions that have already been mapped to an established process. In most situations, when local agency street or roadway projects are located on a locally owned facility and funded only by local resources, the local agency guidelines and standards govern the Facility Type Performance Measure Definition Geometric Design Elements Basic Relationship Potential Performance Trade-offs Evaluation Resources Rural two-lane segments Horizontal alignment shoulder width and composition, shoulder type, lane width, type and location of auxiliary lanes, rumble strips, roadside design features, lighting, two-way left-turn lane, grade See HSM HSM Chapter 10 Rural two-lane intersection Intersection form, control type, and features, number and types of lanes, lighting, skew See HSM HSM Chapter 10 Rural multilane segments Shoulder width and composition, shoulder type, lane width, lane and shoulder cross slopes, median provisions, lighting, two-way left-turn lane See HSM Some safety improvements reduce mobility Rural multilane intersection Crash frequency and severity Expected number and severity of crashes Intersection form, control type, and features; number and types of lanes; lighting; skew See HSM Reduce access (e.g., reducing driveway density, or negatively affect another performance measure HSM Chapter 11 Urban/ suburban segments Basic cross section, access points and density, fixed object density, median provisions, on-street parking See HSM HSM Chapter 12 Urban/ suburban intersection Intersection form, control type, and features; number and types of lanes; signal phasing See HSM HSM Chapter 12 Freeway segments Lane width, shoulder width and composition, ramp spacing, use of auxiliary lanes, ramp entrance/exit configurations See final report for NCHRP Project 17-45* Final report for NCHRP Project 17-45 *; NCHRP Report 687 Interchange Interchange form and features, number and types of lanes, horizontal alignment, cross section, roadside See final report for NCHRP Project 17-45 * * The contractor’s final report for NCHRP Project 17-45 (TTI and CH2M-Hill 2012) Source: Exhibit 4-9 in NCHRP Report 785 (Ray et al. 2014) Exhibit 3-10. Safety performance measures.

64 Design Guide for Low-Speed Multimodal Roadways design. If a locally funded project is located on a facility owned by another agency (such as a state or federal-aid facility owned by a state DOT), the design guidelines and processes of the agency that owns the facility may need to be followed. Other projects on local or state/ federal facilities may be funded by a combination of local, state and federal funds, in which case a state DOT’s “local program” processes, standards and guidelines may be required to be followed in the design process. Projects located on the NHS must use the Green Book (AASHTO 2011a) as the design standard; however, strict adherence to every design criterion contained in the Green Book may not always be obligatory for the low- and intermediate- speed roadways. 3.6.1 Selecting the Appropriate Design Process for the Project This Guide identifies three credible sources, each of which outlines particular approaches to the design of multimodal projects: • Designing Walkable Urban Thoroughfares: A Context-Sensitive Approach (ITE 2010a); • The Urban Street Design Guidelines (USDG) developed by the City of Charlotte, North Carolina, and profiled on FHWA’s Context Sensitive Solutions website (FHWA n.d.b); and • NCHRP Research Report 839 (Neuman et al. 2017). All three sources have a key feature in common: they fully consider and address the needs of all current and future users throughout the project development and design process. Because certain elements of each approach may be useful to a designer, specific elements of one process may be combined with elements of others to create a multimodal design approach that is tailored to an agency’s specific needs. No two projects are the same, so this Guide suggests that designers and planners carefully develop a tailored approach for each individual project. The constants among the three sources’ design approaches are: • Identifying alternatives in the planning phase of a project; • A focus on stakeholder identification and engagement; • Involvement of multidisciplinary design teams; and • A thorough evaluation of the performance of all modes using the right-of-way. This Guide simplifies each of these approaches to allow a streamlined process; however, the designer is encouraged to reference the original source documents for additional detail as needed. The approaches described in the ITE and City of Charlotte documents apply more qualitative information to interpret and integrate the needs of motorized vehicles with the other anticipated users, project context and community goals. These approaches are better aligned with small- and mid-sized local agency projects than with larger-scale state and federal-aid projects. NCHRP Research Report 839 also presents a multidisciplinary team approach, but the process described is somewhat more detailed, quantitative and structured around a design project development process that is typical for larger roadway projects. 3.6.2 Designing Walkable Urban Thoroughfares: A Context Sensitive Approach These guidelines from ITE (2010a) present a roadway design process that, for simplicity, is organized into five stages. The suggested stages are intended as an iterative process that ideally requires collaboration with the public, stakeholders and a multidisciplinary team of profession- als throughout the entire design process. The guidelines in the ITE document primarily address urban streets with operating speeds at or below 35 mph and with a goal to be “walkable,” but the

Balancing User Performance in Low- and Intermediate-Speed Environments 65 project team for this Guide suggests that elements of this approach can be used for the design of all low- and intermediate-speed roadway types under any context. • Stage 1: Review area transportation plans. The area transportation plan normally entails development of land use and travel demand forecasts and testing of network alternatives in considering context and community objectives. Often this stage is already available and serves as a direction or resource for the roadway designer. This first stage provides the overall basis for roadway design. The transportation plan establishes guiding principles and policies for the broader community and region. It develops and evaluates the network to ensure the transportation system accommodates projected land use growth. The plans for a project should identify performance measures for each mode of transpor- tation at the intersection, corridor and network level and should identify how the network supports the community’s key goals. The plan should identify and prioritize discrete roadway projects from which the project development process begins. If an area transportation plan has not been prepared, ideally one should be prepared as part of the roadway design process. Area transportation plans can be in the form of regional transportation plans, comprehen- sive or general plans, bicycle or pedestrian plans, or focused district, area, or specific plans. • Stage 2: Understand community vision for context and roadway. In this stage, the designer collaborates with the public, stakeholders and a multidisciplinary team to develop specific goals and objectives for the project. If the community in which the project is located has developed a vision and established goals and objectives, this stage entails a thorough knowl- edge and understanding to ensure that the project achieves that vision. This stage requires review of planning documents, transportation and circulation plans, and land use and zon- ing plans or codes. Through the assembled community vision, a multidisciplinary team can determine both the existing and future context for the area served by the roadway. The future context should define the long-term transportation and overall “place-making” function of the right-of-way and roadway. If the community lacks a vision, desires a change, or requires further detail in the project area, then an opportunity exists to use a public and/or stakeholder process to answer questions that will form the basis of a vision: – What do we want this area of the community to be? – What do we want this portion of the community to look like? – How do we want this project to support the desired function of the community? Frequently, it is desirable to use a participatory process to develop concepts and alter- natives, even if a vision exists. This establishes public ownership in the project and helps meet the requirements of the National Environmental Policy Act (NEPA) and other federal requirements, where applicable. The process for working with the public and stakeholders to develop a vision is not included in the ITE report (2010a). However, resources are available to explain the process, such as FHWA’s Public Involvement Techniques for Transportation Decision-Making (FHWA 2015b). • Stage 3: Identify compatible roadway types and context zones. The tools necessary for this stage are described in Chapter 4 of the ITE report (2010a) and are addressed in this Guide. Stage 3 relies on an understanding of the existing and future land use contexts identified in Stage 2. Together, stages 2 and 3 result in the identification of opportunities, design controls and constraints that will dictate roadway design elements and possible project phasing. The source report can help guide the roadway design team through the process of iden- tifying the context and the alternative roadway types best suited for the identified context zone. The initial relationship between the context zone and the roadway is tentative, given the iterative nature of Stage 3, which involves comparing needs with constraints, identifying trade-offs, and establishing priorities for design performance outcomes.

66 Design Guide for Low-Speed Multimodal Roadways Stage 3 also involves close examination of all modal requirements (e.g., transit, bicycle, pedestrian and freight needs) and establishes design controls such as design traffic volumes for all users, speed, corridor-wide operations, right-of-way constraints and other fundamen- tal engineering controls. Specific steps in Stage 3 include: – Determining the context zone(s) within which each segment of the roadway is located, and – Selecting the appropriate cross section features based on the context zone(s) and purpose of the roadway. A project may encompass more than one context zone, and context zones will likely vary along the length of a large corridor project. Longer roadways will likely need to be divided into segments with varying design parameters and elements. Existing and projected, context zones can be determined from a community or regional comprehensive plan if one is avail- able. In the absence of such a plan, the context zones can be derived from the description of the function and configuration, the type of the properties and buildings fronting the road- way, and whether the context is predominantly residential, commercial or possibly a combi- nation including other land use types. The purpose of the roadway, including its functional designation, also can be determined from the area plan. Context definitions within the roadway’s planning document will assist a multidisci- plinary team in developing the character and general design parameters of the roadway. The roadway’s functional classification establishes the role of the roadway in the transportation network. The roadway cross section and multimodal features help determine certain design controls (e.g., target speed), the physical design of the roadway and the design elements that support the activities of adjacent uses. For urban roadways in walkable communities, the combination of roadway type, functional classification and context zone drives the selection of appropriate general design parameters. The parameters are described in detail in several chapters of the source document (ITE 2010a). • Stage 4: Develop and test the initial roadway concept. Understanding the balance between the regional functions and local needs of the roadway is crucial to selecting the appropriate design criteria and preparing the initial roadway design concept. Stage 4 determines whether the street cross section concept of initial width and design features is appropriate. This stage feeds back into the previous stages if the evaluation of the concept suggests the need to change the initial roadway type or modify the system design. In this stage, a multidisciplinary team uses the design parameters identified by the context zone/roadway type combination selected in Stage 3 to determine the basic elements of the roadway and roadside that affect its width, including on-street parking, bicycle facilities, number and width of travel lanes, median and general configuration of the roadside elements. The design team then tests and validates the initial concept at the corridor and network level of performance for all modes. A successful roadway concept is one that, when viewed as part of an overall system, maintains acceptable system-wide performance for all users, even though the individual roadway intersections or segments may experience some congestion for one or more user types. Network performance should include multimodal performance measures. Chapter 3 of the source report describes the role of the roadway in the network and references network connectivity guidelines. Evaluation of the roadway at the corridor and network level will either validate the initial concept or indicate the need to revisit the context zone/roadway type relationship or modify the design parameters. The evaluation might even indicate the need to revise regional or sub- regional land use and circulation plans. • Stage 5: Develop a detailed roadway design. Once a successful initial concept has been devel- oped and validated in Stage 4, the process leads to the final stage: developing the detailed design elements of the traveled way and roadside. Stage 5 involves using the guidance of the source report to integrate the design of the street components, context, street-side, traveled way and intersections.

Balancing User Performance in Low- and Intermediate-Speed Environments 67 This stage also is iterative, resulting in one or more cross sections for various segments of the project. Stage 5 leads into the preliminary and final engineering steps, which include: – Identifying the available right-of-way, desired right-of-way and any constraints; – Designing the traveled way and roadside elements, including an evaluation of trade-offs as may be necessary if right-of-way is constrained; – Designing the street-side elements, which requires an understanding of the characteristics and activity of the adjacent existing or future context; and – Assembling the roadway components—an iterative process, particularly in constrained rights-of-way, to balance LOS and QOS to all modes. 3.6.3 Urban Street Design Guidelines, City of Charlotte, North Carolina The City of Charlotte’s USDG are based on the understanding that various stakeholders have different expectations of what makes streets “good” or even “great” (FHWA n.d.b, City of Char- lotte 2007b). The USDG guidelines stress that the design team must assess the expectations of a vari- ety of stakeholders for the final street design and operations to ensure that the design best reflects the roadway’s contexts and intended functions. Charlotte also uses the guidelines to ensure that the design of the city’s streets provides for the safety and comfort of all users to the best extent possible. The six-step process outlined in the USDG consolidates traditional city planning, urban design and transportation planning activities into a sequence of fact-finding and decision-making steps. This process for planning and designing streets was intended to support the creation of “more streets for more people” (City of Charlotte 2007b). The identified performance outcomes of the USDG process include (City of Charlotte 2007b): 1. Ensuring that the perspectives of all stakeholders interested or affected by streets are seriously consid- ered during both the planning and design process for existing or future streets; 2. Defining a clear sequence of activities to be undertaken by staff, consultants and stakeholders; 3. Remembering that this . . . process . . . is much more geared toward [achieving future goals and out- comes rather than what currently exists and how streets were designed in the past]; 4. Verifying that the inevitable trade-offs affecting objectives, benefits, costs, and impacts are well docu- mented so that the recommendations made by staff, [design] consultants or stakeholders are based on understanding the direct effects on specific modes of travel and/or land use intentions; and 5. Always striving to create not only more streets, but also more complete streets that are good for all modes of travel, and even some great streets that are remarkable because of the very effective and favor- able ways that the adjacent land uses and transportation functions of those streets support each other. The design process described in the USDG provides great flexibility to decision makers “to ensure that the resulting streets are appropriately based on the existing and proposed land use and transportation contexts” (City of Charlotte 2007b). This flexibility can encourage creative solutions as land use planners, transportation planners and engineers collaborate in thinking through the implications of alternative street designs. In Charlotte, the six-step process has primarily been applied to planning and designing the “non- local” street types (e.g., main streets, avenues, boulevards, and parkways) that typically have func- tional classifications as arterial and collector roadways. Exhibit 3-11 outlines the six-step process. Charlotte’s approach to project design starts with area planning, which provides “opportunities to integrate the planned land use and transportation characteristics on an area-wide network basis” (City of Charlotte 2007b). If sufficient information is available about future land use context and future transportation context, the USDG encourages the planning team to “specify the actual cross sections for all non-local streets in the area plan” while recognizing that “retrofitting a non-local street with limited right-of-way through an existing neighborhood will be more complicated and require a more rigorous design alternatives trade-off analysis” (City of Charlotte 2007b).

68 Design Guide for Low-Speed Multimodal Roadways 3.6.4 Applying the Six-step USDG Process Three assumptions are built into the USDG six-step process (City of Charlotte 2007b): 1. The process will involve a variety of stakeholders. The number of stakeholders and discussions will vary, depending on the magnitude and consequences of the street(s) to be designed. 2. The resulting street will be as “complete” a street as possible, in order to meet [the city’s multimodal objectives]. 3. The steps in the decision-making process will be well documented. The documentation will clearly describe the major trade-offs made among competing design elements, how those were discussed and weighed against each other, and the preliminary and final outcomes. Thorough documentation will ensure that all stakeholders’ perspectives are adequately considered in the final design. In the six-step process, the first four steps encompass an area-wide approach to gathering and assessing the required information, because urban and suburban streets typically are embedded within a surrounding street network and context of land uses. The balance of this section pres- ents the six steps, as described in the USDG (City of Charlotte 2007b): Step 1: Define the Existing and Future Land Use and Urban Design Context The classification and ultimate design of any street should reflect both the existing and expected future land use contexts. These existing and future contexts should be considered from the broadest, area-wide perspective down to the details of the immediately adjacent land uses. A street is likely to be classified and/or designed differently if it is in an area planned for higher density develop- ment, such as a transit station area, versus in [a neighborhood with limited development changes anticipated]. Source: Urban Street Design Guidelines (City of Charlotte 2007b) Exhibit 3-11. The six-step process for applying Charlotte’s USDG.

Balancing User Performance in Low- and Intermediate-Speed Environments 69 The following questions regarding the intensity and arrangement of existing and future land uses in the area surrounding the street to be designed should be addressed by the plan/design team: • What does the area look like today? • What are today’s land use mixtures and densities? • What are the typical building types, their scale, setbacks, urban design characteristics, relation to street, any special amenities, etc.? • Are there any particular development pressures on the area (the nature of this may vary according to whether the area is a “greenfield” versus an infill area and this type of information is particularly impor- tant in the absence of an area plan)? What, if anything, can be gleaned from permit data, for example, about the nature of the emerging land use context? • What are the “functions” and the general circulation framework of the neighborhood and adjacent areas? • Is there a detailed plan for the area? • If so, what does the adopted, detailed plan envision for the future of the area? • Does the plan make specific recommendations regarding densities, setbacks, urban design, etc.? • Are there any other adopted development policies that would affect the classification of the street segment? Step 2: Define the Existing and Future Transportation Context The transportation assessment should consider both the existing and expected future conditions of the transportation network adjacent to or affecting the street to be designed. The recommended design should reflect the entire transportation context (function, multimodal features, form), rather than that related strictly to capacity on a given segment. The following questions regarding existing and future transportation conditions should be addressed by the plan/design team: • What is the character of the existing street? How does the street currently relate to the adjacent land uses? • How does the street currently function? What are the daily and hourly traffic volumes? Operating and posted speeds? What is the [LOS] for pedestrians? Cyclist? Motorists? • What are the current design features, including number of lanes, sidewalk availability, bicycle facilities, traffic control features, street trees, etc.? • What, if any, transit services are provided? Where are the transit stops? • What is the relationship between the street segment being analyzed and the surrounding network (streets, sidewalks, transit, and bicycle connections)? • Are there any programmed or planned transportation projects in the area that would affect the street segment? • Are there any other adopted transportation policies that would affect the classification of the street segment? Step 3: Identify Deficiencies Once the existing and future land use and transportation contexts are clearly defined and understood from an area-wide perspective, the plan/design team should be able to identify and describe any deficien- cies that could/should be addressed by the new or modified street. This step should consider all modes and the relationship between the transportation and the land use contexts. From the information provided in the first two steps, “deficiencies” might include, but are not limited to: • Gaps in the bicycle or pedestrian network near or along the street segment; • Gaps in the bicycle or pedestrian network in the area (which may increase the need for facilities on the segment because of the lack of alternative routes); • Insufficient pedestrian or bicycle facilities (in poor repair, poorly lighted, or not well buffered from traffic); • Gaps in the overall street network (this includes the amount of connectivity in the area, as well as any obvious capacity issues on other segments in the area . . .); • Inconsistencies between the amount or type of transit service provided along the street segment and the types of facilities and/or land uses adjacent to the street; and • Inconsistencies between the existing land uses and the features of the existing or planned street network. Step 4: Describe Future Objectives This step synthesizes the information from the previous steps into defined objectives for the street project. The objectives could be derived from the plans and/or policies for the area around the street, as well as from the previously identified list of deficiencies. The objectives will form the basis for the street classification and design.

70 Design Guide for Low-Speed Multimodal Roadways In addition to the general intent of providing complete streets, the following issues should be consid- ered in defining the specific objectives: • What existing policies might or should influence the specific objectives for the street? • What conditions are expected to stay the same (or, more importantly, what conditions should stay the same)? • Would the community and the stakeholders like the street and the neighborhood to stay the same or to change? • Why and how would the community and the stakeholders like the street and the neighborhood to change? • Given this, what conditions are likely to change as a result of classifying the street (exactly how will the street classification and design support the stakeholders’ expectations)? Step 5: Recommend Street Classification and Test Initial Cross Section At this point, the plan/design team recommends the appropriate USDG street typology. . . . [Charlotte’s guidelines use street “typologies” that are used based on the previous steps.] The rationale behind the classification should be documented. This step should also include a recommendation for any neces- sary adjustments to the land use plan/policy and/or transportation plan for that area. Since the street type and the ultimate design are defined, in part, according to the land use context, subsequent land use decisions should reflect and support the agreed-upon street type and design. The initial cross section should be defined based on the recommended street typology, keeping in mind that some typologies allow more than one option. Once the preferred option is identified, the ideal cross section will typically include the design features with their preferred dimensions specified for that street type. The initial cross section should then be tested against the land use and transportation contexts and the defined objectives for the street project. At this point, any constraints to the provision of the initial preferred cross section should also be identified, including: • Lack of right-of way, • Existing structures, • Existing trees or other environmental features, • Topography, and • Location and number of driveways. This step should clearly identify which constraints may prohibit the use or require refinement of the initially defined cross section. Step 6: Describe Trade-offs and Select Cross Section If the initial, “preferred” cross section can be applied, then this step is easy: the initial cross section is the recommended cross section. In many cases, though, the initial cross section will need to be refined to better address the land use and transportation objectives, given the constraints identified in Step 5. Sometimes, the technical team will develop more than one alternative design. In that case, these multiple alternatives should be presented to the stakeholders for their input. Any refinements to the initial cross section (or alternatives) should result from a thoughtful consid- eration of trade-offs among competing uses of the existing or future public right-of-way [from all user perspectives]. The trade-offs should be related to the requirements of each group of stakeholders and the variety of design elements that can best accommodate those requirements. [A matrix in the USDG document provides a] listing of the general expectations of various stakeholders about streets and the elements that might achieve those expectations. At the least, the requirements and elements listed in that matrix should be considered in any trade-off discussion, though that list should not be considered comprehensive. The specific method of evaluating the trade-offs is left open to the plan/design team, as long as the method/discussion/analysis is documented. All perspectives should receive equal consideration and accountability in the planning and design process. Proper documentation will also generate information useful for future street design projects that might have similar characteristics, objectives, or constraints. Once the trade-offs are evaluated, the team should be able to develop a refined cross section and sug- gested design treatments. The culmination of all the previous steps, including any additional stakeholder comments, should provide sufficient rationale to select the design alternative that best matches the con- text and future expectations for the street project.

Balancing User Performance in Low- and Intermediate-Speed Environments 71 The steps outlined in Charlotte’s USDG suggest that there is a linear process leading to an ideal solution. Realistically, in some instances the process may not follow the exact sequence described above. Some information may not be available or may not be applicable to project conditions. Nonetheless, the intent of the six-step process is to ensure that the existing and future contexts are given adequate consideration, that any related plans are modified to reflect the outcome, and that all perspectives are given equal consideration in the process. The approach described in this Guide for large-scale street projects also can be applied to smaller-scale or short-term projects or processes. In those cases, an “abbreviated” version of the six steps can be used to reach decisions. An abbreviated process will necessarily involve a shorter timeframe and will likely involve fewer stakeholders, but it is still important to consider all user perspectives and document any necessary trade-offs. The intent is to apply this thought process to the design of a city’s emerging multimodal street network in a way that accounts for all users, whether the full six-step process is followed or an abbreviated version. 3.6.5 NCHRP Research Report 839: A Performance-Based Highway Geometric Design Process NCHRP Research Report 839 (Neuman et al. 2017) outlines a recommended geometric design process for performance-based design. The report notes that successful completion of critical parts of the overall design process are essential to the success of the roadway design process. NCHRP Research Report 839 also references NCHRP Report 480: A Guide to Best Practices for Achieving Context Sensitive Solutions (Neuman et al. 2002), noting the earlier report’s documen- tation of a project development framework that reflects the recent evolution of roadway design. NCHRP Report 480 suggests that the critical success factors to roadway project completion are to: • Employ an effective decision-making process; • Reflect community values (i.e., include stakeholders); • Be environmentally sensitive; and • Implement safe and feasible solutions. NCHRP Research Report 839 suggests that these critical success factors align well with the goals of performance-based design, and that they are reflected in the following recommended steps of the roadway design development process (Neuman et al. 2017): • Step 1: Define the transportation problem or need; • Step 2: Identify and charter all project stakeholders, including: – Internal agency stakeholders, – External agency stakeholders, – Other external stakeholder groups or agencies, and – Directly affected stakeholders. • Step 3: Develop the project scope, including refinement and confirmation of the project’s Problem Statement or Needs Statement; • Step 4: Determine the project type and design development parameters; • Step 5: Establish the project’s context and geometric design framework, including: – A framework for the geometric design process for new construction and reconstruction, – Project evaluation criteria (developed within the context and framework), – Decision-making roles and responsibilities, – Basic geometric design controls (e.g., design or target speed), and – Basic design controls (e.g., design traffic volumes, design LOS or operating condition, and road user attributes). • Step 6: Apply the appropriate geometric design process and criteria for – Roads on new alignment, which are designed with a unique process and set of criteria, – Projects involving existing roads (e.g., reconstruction, 3R), and – Developing a project technical approach.

72 Design Guide for Low-Speed Multimodal Roadways • Step 7: Designing the geometric alternatives, which involves – Assembling an inclusive and interdisciplinary team, – Focusing on and addressing the need (or solving the problems) within the project’s context conditions and constraints. • Step 8: Design decision-making and documentation, including independent quality and risk- management processes; and • Step 9: Transitioning to preliminary and final engineering of selected alternative design cri- teria, elements and features. NCHRP Research Report 839 also presents two additional steps. The additional steps relate primarily to agency operations and maintenance, however, and they are not discussed in this Guide. 3.7 Balancing MMLOS As summarized by Exhibit 3-3, numerous tools are available to designers as they develop and evaluate various service levels and performance metrics for all users in multimodal proj- ects. Some of these tools require significant data collection and analysis, whereas others require substantially less data and are more qualitative. Using these tools can provide a wealth of infor- mation about the level, quality and performance of each mode served by a project design alterna- tive; however, deciding which tool is best for each specific project can be a challenge. The type and depth of MMLOS and multimodal QOS analysis used in the geometric design process can vary widely. A designer’s choices are influenced by several factors, including but not limited to: • Project funding, budget and source; • Project type and size; • Desired performance outcomes; • Demand level of modes (existing and planned); • Project context (existing and planned); • Community or corridor plans, goals and policies; • Community issues and concerns; • Condition of current roadway(s); • Right(s)-of-way available; and • Utility conditions. The most important aspects of the selected design evaluation approach are that the needs, desires and performance goals of all legal users are identified at some level, and that they are considered as an integral part of the design process. Understanding current and future user demands, how those user movements interact with and affect each other, and how performance across all modes is affected by the various design alternatives is essential to achieving a well-balanced and effective multimodal design. Trade-offs in LOS, QOS and other performance metrics normally will be required to determine the “best- fit” design alternative given the project’s purpose and need and the community’s priorities. 3.7.1 The North Carolina Complete Streets Planning and Design Guidelines The North Carolina Complete Streets Planning and Design Guidelines (North Carolina DOT 2012) recommends that all identified design alternatives be tested against the land use and trans- portation context and the range of objectives and outcomes for the project to determine any

Balancing User Performance in Low- and Intermediate-Speed Environments 73 inconsistencies or constraints. The Complete Streets guidelines note that solutions within various alternative scenarios will likely vary by cost, right-of-way needs and/or how various modes are accommodated, and that, preferably, these variations will require an evaluation and description of trade-offs before selection of the recommended alternative. Ideally, the evaluation and description of trade-offs will have been considered or conducted during the participatory stakeholder process required to meet NEPA requirements. It should occur prior to publication of any NEPA document. While preliminary design concepts are under development, it is feasible to make a broad comparison of trade-offs in travel way and roadside cross sections, right-of-way needs, ability of the alternatives to meet the identified objectives, and so forth. By the end of this process, the reasons behind the selected cross section should be transparent and understood by all stakeholders. North Carolina’s guidelines recommend that, at a minimum, the following items be considered (North Carolina DOT 2012): • Consistency with local context, land use and transportation plans and policies, and project objectives . . . ; • Balanced modal capability (to achieve functionality for all users); • Accessibility to achieve functionality for all users; • Right-of-way availability; • Environmental (natural and human) considerations; and • Overall cost. 3.7.2 Balancing MMLOS for Large and Complex Projects Larger, more costly and more complex projects including accommodation for non-motorized users generally will benefit from investing in the 2016 HCM 6th Ed.’s multimodal analysis appli- cations using the medium-level analysis methods. In addition to providing performance mea- sures and computational methods for motorized vehicles, the HCM 6th Ed. also provides a variety of measures that can be used for pedestrians and bicycles on differing on- and off-street facilities. As research has not yet been conducted to quantify the pedestrian and bicycle experi- ence for all types of HCM system elements, not every mode is addressed in every section of the pedestrian, bicycle and transit analysis and guidance. (For more discussion on use of the HCM for multimodal analysis, see the section on current practice in this chapter of the Guide.) The HCM’s pedestrian and bicycle performance measures focus on (1) the impacts of other facility users on pedestrians and bicyclists and (2) facility design and operation features under the control of a transportation agency. Some analysts may also be interested in the effects of urban design on pedestrians’ and bicyclists’ potential comfort and enjoyment while using a facil- ity. In those cases, additional measures, such as the Mineta Transportation Institute’s Low-Stress Bicycling and Network Connectivity report (MTI 2012), HPE’s Walkability Index (ITE 2010b) or the BEQI (SFDPH 2009, SFDPH 2012) could be appropriate tools for additional analysis. The HCM also provides a transit LOS measure for evaluating on-street public transit service in a multimodal context. The TCQSM 3d Ed. provides a variety of performance measures, com- putational methods and spreadsheet tools to evaluate the capacity, speed, reliability and QOS of on- and off-street transit service (Kittelson and Associates, Inc., et al. 2013). The four-volume HCM provides the most detailed analysis tools available to the designer. Volume 3, “Interrupted Flow,” addresses urban street facilities in Chapter 16. Volume 4, the “Applications Guide,” includes thirteen separate supplemental chapters. Among these supple- mental chapters, Chapter 29, “Urban Street Facilities: Supplemental” can be used as a companion chapter to Volume 3, Chapter 16. Volume 4, Chapter 29 uses five example problems to demonstrate the application of the meth- odologies to conduct a multimodal evaluation of urban street performance and an evaluation of urban street reliability. The examples illustrate the multimodal facility evaluation process. Four

74 Design Guide for Low-Speed Multimodal Roadways of the examples demonstrate an operational level analysis, and the fifth example demonstrates a planning-level analysis. The planning and preliminary engineering analysis is identical to the operational-level analysis in terms of the calculations, except that default values are used when field-measured values are not available. The examples address the following project scenarios: • Automobile-oriented urban street (operational-level analysis); • Widen the sidewalks and add bicycle lanes on both sides of facility (operational-level analysis); • Widen the sidewalks and add parking on both sides of facility (operational-level analysis); • Urban street reliability under existing conditions (operational-level analysis) and • Urban street reliability strategy evaluation (using planning-level analysis). Each example calculates individual modal levels of service, but they are not typically com- bined into a single comprehensive LOS for the project because there is concern that doing so would disguise the disparities in the perceptions of QOS for the individual modes. This Guide suggests that each project be analyzed specific to its context, expected user modes and area char- acteristics. Because no two projects are the same, a comprehensive LOS could thwart the goals of meeting the LOS or QOS of a vulnerable user. 3.8 Design Process in Constrained Rights-of-Way A primary roadway design challenge is balancing all of the desired design elements of the road- way within the available or planned right-of-way. The roadway design process will assist in deter- mining the desired elements to serve all users within the cross section, but actual conditions often limit the width of the traveled way and roadside such that difficult choices must be made. Design- ing roadways in constrained rights-of-way requires prioritizing the design elements and empha- sizing the higher priority elements in constrained conditions. Higher-priority design elements are those considered critical to making the roadway meet the primary vision and context-sensitive objectives of the community. Lower-priority elements also are important, but have less influence on achieving the objectives and can be removed in situations with insufficient right-of-way. In urban and suburban contexts, the width of the public right-of-way often varies along the roadway, making the designers’ choices even more challenging. When the width of the right- of-way is limited or varies throughout a project, it is useful to prioritize design elements and develop a series of varying cross sections that are categorized as follows: • Optimal conditions (i.e., sections without right-of-way constraints that can accommodate all desirable elements); • Predominant (i.e., sections of the predominant right-of-way width in the corridor that can accommodate all of the higher priority elements); • Functional minimum (i.e., typically constrained sections that can accommodate most of the higher priority elements); and • Absolute minimum (i.e., severely constrained sections that can accommodate only the highest-priority design elements without changing the type of roadway). If roadway sections are sufficiently constrained that they fall below the absolute minimum, or if most sections of the right-of-way are categorized at or below the absolute minimum, the designer should consider (1) changing the roadway to a different type while attempting to maintain basic function, (2) converting the roadway to a pair of one-way roadways (a couplet) or (3) seeking other solutions that achieve the community vision. These options may require revisiting some of the earlier steps of the design process, potentially even requiring a review of the community vision for the roadway and the area transportation plan or identifying a new context zone/roadway relation- ship. If the vision for the corridor is long range, then the necessary right-of-way may need to be attained over time as the adjacent properties redevelop. Under these circumstances, the optimal

Balancing User Performance in Low- and Intermediate-Speed Environments 75 (or the predominant) roadway width can be phased in over time, beginning with the functional or absolute minimum design in the initial phase. Given constrained conditions, it might be tempting to minimize the roadside width and pro- vide only the minimum pedestrian throughway (5 ft.). In urban areas, however, even under constrained conditions, it is critical to provide at least a minimum-width furnishings zone to accommodate street trees, utility poles and other appurtenances. If a furnishings zone is not provided, trees, utilities, benches, shelters and other street paraphernalia might encroach into the throughway for pedestrians or result in an inadequate roadside width when the community’s vision for the context zone is ultimately achieved. Sources of Additional Information These publications supplement the sources listed at the end of Chapters 1 and 2. AASHTO. 2010. Highway Safety Manual (HSM), with 2014 supplement. American Association of State Highways and Transportation Officials, Washington, D.C. Cambridge Systematics, Inc. and High Street Consulting Group. NCHRP Report 660: Transportation Performance Management: Insight from Practitioners. Trans- portation Research Board of the National Academies, Washington, D.C., 2010. FHWA. n.d.e. “Performance-Based Planning Focus Area” webpage. Online: https://www.planning.dot.gov/focus_performance.asp. FHWA. 2010a. Advancing Metropolitan Planning for Operations: An Objectives- Driven, Performance-Based Approach – A Guidebook. Office of Operations, Federal Highway Administration, U.S. Department of Transportation, Wash- ington, D.C. Online: https://ops.fhwa.dot.gov/publications/fhwahop10026/. FHWA. 2013d. Performance Based Planning and Programming Guidebook. Federal Highway Administration, U.S. Department of Transportation, Wash- ington, D.C. Online: https://www.fhwa.dot.gov/planning/performance_based_ planning/pbpp_guidebook/. Middleton, S. 2015a. Final Report of the Peer Exchange on “Cross-Modal Project Prioritization” (December 16–17 2014, Raleigh, NC). Online: https://www. planning.dot.gov/Peer/NorthCarolina/NCDOT_cross-modal_12-16-14.pdf. Middleton, S. 2015b. Final Report of the Peer Exchange on “Establishing and Integrating Performance Measures” (April 27–28, 2015, Dimondale, MI). FHWA-HEP-15-052; DOT-VNTSC-FHWA 15-18. Online: https://planning.dot.gov/ Peer/michigan/Dimondale_04-27-15_Perf_Measures.pdf. NADO. 2011. Transportation Project Prioritization and Performance-based Plan- ning Efforts in Rural and Small Metropolitan Regions. National Association of Development Organizations, Washington, D.C. Online: https://www.nado.org/ wp-content/uploads/2011/11/RPOprioritization.pdf. Waldheim, N., Wemple, E., and J. Fish. 2015. Applying Safety Data and Analysis to Performance Based Transportation Planning. FHWA-SA-15-089. Federal High- way Administration, U.S. Department of Transportation, Washington, D.C.