Design Guide for Low-Speed Multimodal Roadways (2018) / Chapter Skim
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From page 76... ...
76 4.1 General Considerations for Traveled Way Design for All Users The discussion in this section provides information and guidance to the design process for the traveled way of any roadway and street project serving a mix of users with a vehicle design speed of 45 mph or lower. 4.1.1 Roadway Uses, Users and Activities in Low- and Intermediate-Speed Environments As discussed in previous chapters of this Guide, designing road and street facilities that effectively serve all current and planned users in low- and intermediate-speed environments can be a challenging process.
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From page 77... ...
Traveled Way Design Guidelines 77 areas adjacent to the traveled way and which may include facilities for pedestrians, bicyclists, transit access and other elements that support the land use context. 4.1.2 Relationship of Traveled Way and Roadside Environments A roadway design project may involve improvements to the traveled way, to the roadsides, or to both the traveled way and the roadsides.
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From page 78... ...
78 Design Guide for Low-Speed Multimodal Roadways needs, community goals and other factors may cause the design concept, cross section and design elements to vary throughout the roadway's length. Project alternatives should emerge from a full understanding of the relationships between the roadway, the adjoining properties, the character of the broader area and other unique project circumstances, values or objectives.
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From page 79... ...
Traveled Way Design Guidelines 79 Source: North Carolina DOT (2012) Exhibit 4-1.
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80 Design Guide for Low-Speed Multimodal Roadways and roadways, and the type of ground-floor land use in multistory buildings affect context and multimodal activity. Contexts that give a lower priority to walking generally are developed to be more internally oriented and may even minimize interaction with adjacent roadsides and sidewalks.
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From page 81... ...
Traveled Way Design Guidelines 81 Guidelines for selecting the context to be used to inform the geometric design process include the following: • Consider both the existing conditions and the plans for the future, recognizing that roadway improvements usually last longer than development; • Assess area plans and review general, comprehensive and specific plans, zoning codes and community goals and objectives which may provide detailed guidance on the vision for the area; • Compare the area's predominant land use patterns, building types and land uses to the characteristics presented in Exhibit 4-3; • Pay particular attention to residential densities and building type, commercial floor-area ratios and building heights; • Consider dividing the area into two or more context zones if a range of land use characteristics suggests multiple context zone types; and • Identify current levels of pedestrian, bicycle and transit activity, and estimate future levels and circulation needs based on the type, mix and proximity of land uses. 4.1.4 Multimodal Network Considerations Project design usually takes place at a much smaller scale than design at the network level, but in the design of multimodal projects it is important to understand the network role of the facility on which the project is located.
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From page 82... ...
82 Design Guide for Low-Speed Multimodal Roadways do not address a facility's role in the mobility of other modes, or how the facility relates to the community and the adjacent land use context. Ideally, network planning is integrated into a comprehensive planning process that concurrently addresses land use, transportation and environmental needs.
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From page 83... ...
Traveled Way Design Guidelines 83 4.1.5 Functional Requirements of Multimodal Roadways Multimodal accommodation can exist on any functional classification of roadway (e.g., arterial, collector, or local) , but this Guide primarily addresses accommodation needs on arterial and collector roadways.
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From page 84... ...
84 Design Guide for Low-Speed Multimodal Roadways Design Characteristic Typical Multimodal Roadway Design Characteristics by Context Zone Urban Core Urban Suburban Rural Town Design Speed 20 mph–30 mph 25 mph–35 mph 30 mph–45 mph 25 mph–45 mph Target Operating Speed * 20 mph–30 mph 25 mph–35 mph 25 mph–40 mph 25 mph–35 mph Vehicle Lane Widths 10–11 ft.
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From page 85... ...
Traveled Way Design Guidelines 85 Design Characteristic Typical Multimodal Roadway Design Characteristics by Context Zone Urban Core Urban Suburban Rural Town Landscaping/ Green Infrastructure • Typical, although may be limited in constrained settings • Typical, although may be limited in constrained settings • Usually provided at some level, although may be limited or low- maintenance in some settings • Sometimes provided but typically at low levels due to right-of-way constraints Pedestrian Facilities *
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From page 86... ...
86 Design Guide for Low-Speed Multimodal Roadways 4.1.6.1 AASHTO Design Controls The Green Book presents the pedestrian's needs as an important factor in roadway design and recommends that attention be paid to the presence of pedestrians in rural and urban areas. Characteristics of pedestrians that serve as design considerations and controls include walking speed, age (young and old)
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From page 87... ...
Traveled Way Design Guidelines 87 selected corridors and roadway segments is considered a lower priority than other factors, such as walking and biking accessibility, economic development or historical preservation. In those locations, vehicle LOS is a lower priority and higher levels of vehicle congestion are considered acceptable.
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From page 88... ...
88 Design Guide for Low-Speed Multimodal Roadways and access management)
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From page 89... ...
Traveled Way Design Guidelines 89 the effects on roadway traffic. Treatments and priorities for bus transit can vary depending on specific traffic, roadway and environmental conditions.
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From page 90... ...
90 Design Guide for Low-Speed Multimodal Roadways • Curb ramps. Curb ramps facilitate pedestrian access between sidewalks and street crossings, and between sidewalks and accessible on-street parking.
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Traveled Way Design Guidelines 91 • Surface treatments. The PROWAG requires planar and smooth pedestrian access route surfaces.
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From page 92... ...
92 Design Guide for Low-Speed Multimodal Roadways 4.2 Traveled Way Design Element Guidelines for All Users This section of the Guide provides principles and guidance for the design of a roadway's traveled way with multiple users in low- and intermediate-speed environments. On roadways with shoulders and curbs, or shoulders in lieu of curbs, the traveled way as defined also includes the shoulders.
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From page 93... ...
Traveled Way Design Guidelines 93 4.2.1 Traveled Way Cross Section Considerations The goal of traveled way cross section development is to provide an objective and balanced assessment of the impacts, trade-offs and benefits of each alternative on each user mode using the traveled way. These include users that travel along the roadway, users who must cross the roadway (e.g., vehicles, pedestrians and bicyclists)
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From page 94... ...
94 Design Guide for Low-Speed Multimodal Roadways setbacks from the right-of-way line. These context changes usually indicate increasing numbers of non-motorized users traveling along and across the roadway, a need for pedestrian sidewalks and ADA-compliant ramps, turn lane additions to serve an increased number of driveway and intersection turning movements, a possible change from shoulders to curb and gutter, potentially on-street parking, and traffic control changes such as traffic signals and lower speed limits.
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From page 95... ...
Traveled Way Design Guidelines 95 Whether paved or gravel, roadway shoulders typically are associated with rural highway and road classifications, and in some low-density suburban areas where open drainage facilities are preferred over closed drainage underground systems. Paved shoulders like those generally used for higher volume and higher-speed facilities are not generally used for low-speed urban and suburban contexts.
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From page 96... ...
96 Design Guide for Low-Speed Multimodal Roadways The Pedestrian Facilities Guide (AASHTO 2004b) emphasizes the role a curb can play in improving comfort and safety for pedestrians.
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From page 97... ...
Traveled Way Design Guidelines 97 • Most shoulders are not considered pedestrian facilities because they are not intended for use by pedestrians; however, an occasional pedestrian may use the shoulder when necessary (e.g., when a vehicle breaks down)
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From page 98... ...
98 Design Guide for Low-Speed Multimodal Roadways best opportunity to get a 4-ft. or greater paved shoulder in place.
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Traveled Way Design Guidelines 99 recommended ranges for lane width in the urban, low-speed environment (less than 50 mph) normally provide adequate flexibility to achieve a desirable urban cross section without requiring a design exception.
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From page 100... ...
100 Design Guide for Low-Speed Multimodal Roadways potential considerations and provides design guidance for the various types of travel lanes used in low- and intermediate-speed environments. Where streets are designed in areas with a significant level of existing or planned use by nonmotorized users, excessive street width can create barriers for pedestrians and encourage higher vehicular operating speeds.
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From page 101... ...
Traveled Way Design Guidelines 101 balance of community objectives, the street's role in the overall network and the existence or lack of parallel roadways across which traffic can be balanced. • Functional classification.
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From page 102... ...
102 Design Guide for Low-Speed Multimodal Roadways these two variables, a study by Fitzpatrick et al.
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From page 103... ...
Traveled Way Design Guidelines 103 • Where wider curb lanes are required, the designer should consider balancing the total width of the traveled way by narrowing turn lanes or medians to maintain the same overall pedestrian crossing width. • Additional lane width may be necessary for receiving lanes at turning locations with tight curves.
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From page 104... ...
104 Design Guide for Low-Speed Multimodal Roadways 4.2.4.1 Bicycle Lanes • Conventional bike lanes. Bike lanes designate a preferential space for bicyclists using pavement markings and signage (Exhibit 4-9)
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From page 105... ...
Source: NACTO (2014) Exhibit 4-10.
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From page 106... ...
106 Design Guide for Low-Speed Multimodal Roadways by the vertical element. They are differentiated from shared-use paths (and sidepaths)
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From page 107... ...
Traveled Way Design Guidelines 107 barrier between the cycle track and the motorized vehicle travel lane. This design reduces the risk of dooring compared to a bike lane, and it eliminates the risk of a doored bicyclist being run over by a motorized vehicle.
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From page 108... ...
108 Design Guide for Low-Speed Multimodal Roadways 4.2.4.3 Current AASHTO Policy and Guidance • Green Book. The Green Book states, ".
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From page 109... ...
Traveled Way Design Guidelines 109 of FHWA guidance related to barrier-separated preferential lanes formed the basis for the first separated bike lanes and has been expanded on in later FHWA guidance. • Separated Bike Lane Planning and Design Guide.
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From page 110... ...
110 Design Guide for Low-Speed Multimodal Roadways • Forms of separation. Separated bike lanes provide a physical separation from motorized vehicles by a curb, a raised median or a vertical element.
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Traveled Way Design Guidelines 111 roadways are operating today, and focuses on opportunities to make incremental improvements despite the geographic, fiscal and other challenges that many rural communities face. It provides information on maintaining accessibility and MUTCD compliance, while encouraging innovations such as "Yield Roadways" and "Advisory Shoulders" (dashed bicycle lanes)
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From page 112... ...
112 Design Guide for Low-Speed Multimodal Roadways planned to use) the roadway, and how the transit vehicles, their operation and their stops and stations will affect the design of the roadway.
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From page 113... ...
Traveled Way Design Guidelines 113 4.2.6.5 Bus Stop Design Considerations The most typical transit facility accommodation in urban, suburban and some rural roadways is the bus stop. This section of the Guide presents general guidance for the planning and design of bus stops based on current national guidance.
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From page 114... ...
114 Design Guide for Low-Speed Multimodal Roadways • Use landscaping near the passenger boarding area to maximize passenger comfort, but place any landscaping far enough back from the curb face to prevent interference with bus or passenger visibility. All landscaping should be located so as not to obstruct the shelter canopy or obscure sight lines at the bus stop.
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From page 115... ...
Traveled Way Design Guidelines 115 Disadvantages • More difficult to reenter traffic, increasing bus delay and increasing average travel time for buses; • Uses additional space and may require right-of-way acquisition. Buses also may have difficulty pulling parallel to the curb, reducing accessibility, and they may face a greater crash risk pulling back into traffic from the pullout than buses stopped in the traffic lane.
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From page 116... ...
116 Design Guide for Low-Speed Multimodal Roadways The guidelines are based on a review of relevant AASHTO, TRB, and ITE documents, and of design reports provided by various transit agencies. • This Guide.
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From page 117... ...
Traveled Way Design Guidelines 117 various kinds of busways through roadway intersections to enhance safety while maintaining efficient transit and highway operations and minimizing pedestrian delay. Guidance is included for at-grade intersections along busways within arterial street medians; physically separated, side-aligned busways; busways on separate rights-of-way; and bus-only ramps.
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From page 118... ...
118 Design Guide for Low-Speed Multimodal Roadways • Increasing capacity (>30 percent) of roadways; • Reducing vehicle speeds on the roadway; • Providing space for landscaping within the right-of-way; • Providing space to install additional roadway lighting, further improving the safety of the roadway; • Providing space to provide supplemental signage on multilane roadways; and • Potentially reducing cost, as raised medians can be less expensive to build and maintain than pavement.
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From page 119... ...
Traveled Way Design Guidelines 119 and streets notes that local urban streets often do not have medians, but where provided they are primarily used to enhance the environment and to act as buffer strips. The chapter on collector roads and streets notes that medians generally are not provided on rural collector roadways, but offers significant discussion of median use for vehicle traffic operations and safety purposes on urban collectors.
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From page 120... ...
120 Design Guide for Low-Speed Multimodal Roadways the median lane, interspersed with raised landscaped islands to channelize turning traffic, divide opposing lanes of traffic and provide pedestrian refuge where appropriate (such as at mid-block and intersection crossings) ; • At lower urban operating speeds (25 mph to 30 mph)
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From page 121... ...
Traveled Way Design Guidelines 121 intersections are widely spaced or where the nearest intersection crossing location creates substantial out-of-direction travel. Mid-block crossing opportunities also may be preferred because these locations involve no turning vehicles; pedestrians and bicyclists can focus their attention on through-moving vehicles while attempting to cross.
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From page 122... ...
122 Design Guide for Low-Speed Multimodal Roadways The Pedestrian Facilities Guide also identifies three important distinctions between midblock crossings and intersection crossings: • Many more potential crossing locations occur mid-block than at intersections; • Motorists are less likely to expect pedestrians crossing at mid-block; and • Pedestrians with visual impairments have fewer audible clues for determining the best time to cross mid-block (AASHTO 2004b)
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From page 123... ...
Traveled Way Design Guidelines 123 4.2.8.2 Principles and Considerations of Mid-block Pedestrian/Bicycle Crossings General principles and considerations regarding the provision and location of mid-block crosswalks discussed in ITE's Designing Walkable Urban Thoroughfares include the following (ITE 2010a) : • Consider providing a marked mid-block crossing location where protected intersection crossings are spaced greater than 400 ft., or so that crosswalks are located no greater than 200 to 300 ft.
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From page 124... ...
124 Design Guide for Low-Speed Multimodal Roadways 4.2.8.3 Recommended Practice The design of a mid-block crossing location and its associated traffic control depends on numerous factors, including: • The design of the roadway and roadside, • Characteristics of the road users, • Vehicle, pedestrian and bicycle volumes, • Traffic speed, and • Trip purposes and other factors. These factors will influence how the guiding principles are implemented; however, some guidance applies to all mid-block crossing locations.
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From page 125... ...
Traveled Way Design Guidelines 125 Access Board, the same 2 percent maximum for cross slope also applies to the crosswalk (U.S. Access Board 2011)
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From page 126... ...
126 Design Guide for Low-Speed Multimodal Roadways cross (FHWA 2005)
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From page 127... ...
Traveled Way Design Guidelines 127 freeways) and at locations where an at-grade crosswalk is not ideal due to various site characteristics but where pedestrians or bicyclists tend to cross anyway.
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From page 128... ...
128 Design Guide for Low-Speed Multimodal Roadways Source: AASHTO (2014b) Exhibit 4-20.
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From page 129... ...
Traveled Way Design Guidelines 129 Mid-block locations account for more than 70 percent of pedestrian fatalities (FHWA 2008)
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From page 130... ...
130 Design Guide for Low-Speed Multimodal Roadways The AASHTO Bicycle Guide refers to refuge islands as "crossing islands" and states that raised crossing islands are associated with significantly lower pedestrian crash rates at multilane crossings. Although crossing islands can be helpful on most road types, they are of particular benefit at path-roadway intersections in which one or more of the following apply: • High volumes of roadway traffic and/or speeds create difficult crossing conditions for path users; • Roadway width is excessive given the available crossing time; and • The roadway cross section is three or more lanes in width (AASHTO 2014b)
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From page 131... ...
Traveled Way Design Guidelines 131 4.2.9.3 Recommended Practice Where used on two-way streets, median refuge islands should be placed along the centerline of the roadway between the opposing travel lanes (NACTO 2014)
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From page 132... ...
132 Design Guide for Low-Speed Multimodal Roadways such a median is 40 ft.
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From page 133... ...
Traveled Way Design Guidelines 133 Designers should carefully consider the site-specific conditions to determine whether onstreet parking is appropriate for a given block or roadway segment. The designer needs to balance traffic capacity and local access needs when deciding where and when to permit on-street parking.
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From page 134... ...
134 Design Guide for Low-Speed Multimodal Roadways diagonal parking is recommended to mitigate conflicts associated with bike lanes adjacent to angle parking. Additional benefits of back-in diagonal parking for all roadway users include: • Sight distance is improved between exiting motorists and other traffic; • Passengers, including children, are channeled toward the curb when alighting; and • Vehicles' trunks can be more easily loaded and unloaded because they are located at the curb and not in the street.
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From page 135... ...
Traveled Way Design Guidelines 135 4.2.10.3 Recommended Practice for On-Street Parking Lanes Consistent with current AASHTO policy, the desirable width of a parallel on-street parking lane is 8 ft. in most locations.
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From page 136... ...
136 Design Guide for Low-Speed Multimodal Roadways In terms of vehicle operating speeds, where high-speed facilities (50 mph and higher) meet low- or intermediate-speed (45 mph and lower)
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From page 137... ...
Traveled Way Design Guidelines 137 • The transition zone. Located between the rural (i.e., high-speed)
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From page 138... ...
138 Design Guide for Low-Speed Multimodal Roadways These general principles include: • More extensive and aggressive treatments produce greater reductions in speed and crash occurrence than less extensive and passive treatments, and combinations of treatments are more effective at reducing speeds and improving safety than a single treatment; • There should be a distinct relationship between the speed limit and the roadway and roadside characteristics; • As the speed limit is reduced, the change in roadway and roadside characteristics should be apparent enough to reinforce the need for drivers to slow their speeds; • Physical changes to the roadway and roadside are preferred to enforcement and education programs because they have more substantial and lasting effects; • In the perception-reaction area of a speed transition zone, warning and/or psychological treatments (i.e., design and/or contextual elements that communicate suitable operating speed cues to drivers) are more appropriate, and in the deceleration area of a speed transition zone, physical treatments are preferred; and • To maintain a reduction in speed downstream of the speed transition zone, additional treatments are necessary within the intermediate- or low-speed environment.
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From page 139... ...
Traveled Way Design Guidelines 139 with banners, entry signs, and street furniture) can serve as visual cues to influence driver speeds.
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From page 140... ...
140 Design Guide for Low-Speed Multimodal Roadways • Unexpected conflicts should be avoided; • Simple right-angle intersections are best for all users because many intersection problems are worsened at skewed and multilegged intersections; • Access management practices should be used to remove additional vehicular conflict points near the intersection; • Signal timing should consider the safety and convenience of all users; • Intersection designs should integrate geographic constraints; • Special consideration should be given in areas where users include large populations of disabled people, elderly people or children; • Designs should encourage proper travel behavior by all users; and • Intersections should be designed with high legibility and clarity. 4.2.12.1 Skewed Intersections Generally, skewed intersections are undesirable because they introduce the following complications for all users: • The greater travel distance across the intersection increases exposure to conflicts and lengthens signal phases for people on foot and in vehicles; • Skewed intersections require users to crane their necks to see other approaching users, making it less likely that all users will be seen; and • Obtuse angles encourage speeding around corners.
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From page 141... ...
Traveled Way Design Guidelines 141 • Creating pedestrian refuges if the crossing distance exceeds approximately 40 ft.; and • Marking general-use travel lanes and bike lanes with dashes to guide people on bicycles and motorists through a long undefined area. 4.2.12.3 Corner Radii An intersection's corner radius has a significant impact on the comfort and safety of nonmotorized users.
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From page 142... ...
142 Design Guide for Low-Speed Multimodal Roadways 4.2.12.4 Curb Extensions The project team's review of multiple references and best practices suggests that, where on-street parking is allowed, curb extensions should be considered to replace the parking lane at crosswalks. Curb extensions should be the same width as the parking lane.
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From page 143... ...
Traveled Way Design Guidelines 143 maneuver onto a street after stopping at a stop sign, stop bar or crosswalk, drivers will move slowly forward to obtain sight distance (without intruding into the crossing travel lane) , stopping a second time as necessary.
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From page 144... ...
144 Design Guide for Low-Speed Multimodal Roadways corner radius at the right-turn lane often provides the best solution for pedestrians' safety and comfort. Right-turn channelization islands between the through lanes and the right-turn lane can enhance pedestrian safety and access at intersections of multilane traveled ways where trucks make frequent right turns.
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From page 145... ...
Traveled Way Design Guidelines 145 The applicable taper design is a function of the design speed and roadway geometrics. For urban areas, short tapers are preferred because they provided more vehicle queue space and are not as crucial for slow vehicle speeds during peak periods.
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146 Design Guide for Low-Speed Multimodal Roadways particular, roundabouts eliminate left-turn and right-angle crashes, which are common crashes at signalized intersections. Other benefits of roundabouts include: • Reduced delay, travel time, and vehicle queue lengths; • Facilitated U-turns; • Improved accessibility to intersections for people on bicycles through reduced conflicts and vehicle speeds; • Options for people on bicycles of differing abilities to navigate the roundabout; • Reduced maintenance and operational costs (primarily maintenance of landscaping and litter control)
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From page 147... ...
Traveled Way Design Guidelines 147 without traveling over the central island. To accommodate large vehicles, mini-roundabouts can be designed to include a traversable central island and traversable splitter islands.
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From page 148... ...
148 Design Guide for Low-Speed Multimodal Roadways a street or road and its resultant operating speed, in October 2015 FHWA issued a memorandum titled Relationship Between Design Speed and Posted Speed, which provides this guidance: "In urban areas, the design of the street should generally be such that it limits the maximum speed at which drivers can operate comfortably, as needed to balance the needs of all users" (FHWA 2015c)
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From page 149... ...
Traveled Way Design Guidelines 149 4.3.1.2 Passive Measures Commonly used passive speed management measures include: • Synchronized signals to create progression at an appropriate speed; • Radar trailers/speed feedback signs flashing "SLOW DOWN" message when speed exceeds a preset limit (most effective when coupled with enforcement) ; • Visually narrowing road using pavement markings; • Visually enclosing street with buildings, landscaping and street trees; • Variable speed limits (using changeable message signs based on conditions)
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From page 150... ...
150 Design Guide for Low-Speed Multimodal Roadways Chicanes provide opportunities to increase sidewalk space and introduce landscaping and green street elements in the right-of-way. Recommendations for their use include: – Chicanes can be used on two-way streets with one lane in each direction, and one-way roads with no more than two lanes.
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From page 151... ...
Traveled Way Design Guidelines 151 – Generally, speed table design provides 22 ft. of length, with 6-ft.
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From page 152... ...
152 Design Guide for Low-Speed Multimodal Roadways – Consider the reflective characteristics of the pavement; high albedo pavements absorb less heat; – Surfaces such as smooth granite, tile or brick should not be used because they create slippery conditions for bicyclists and pedestrians in wet weather; – Pavements that resist heaving and rutting should be used for locations where heavy vehicles stand or park, or at locations that are particularly susceptible to wear (e.g., high-volume intersections or steep grades) ; and – Concrete bus pads should be considered on high-frequency bus routes.
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From page 153... ...
Traveled Way Design Guidelines 153 Driveway design should consider the roadway functional classification and driveway usage to better accommodate varying roadway contexts, community needs, and existing conditions. In conjunction with the PROWAG (U.S.
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From page 154... ...
154 Design Guide for Low-Speed Multimodal Roadways General design considerations for driveways include: • The number of driveways should be minimized (i.e., consolidated whenever possible) to reduce the number of conflict points for pedestrians and bicyclists and also benefit motorists' safety; • Driveways should normally be designed to look like private driveways, not public street intersections; • Driveways should be located away from intersections; • Driveways should be kept as narrow as possible to minimize exposure to vehicles; • Well-defined driveways clearly mark the area where motorists will be crossing the pedestrians and bicyclists path; • Non-defined vehicle access points with continuous access to parking create a long potential conflict area between pedestrians and motorists, and this added area of ambiguity complicates the motorist's task of watching for these vulnerable users; • Sidewalks and bicycle facilities behind the curb should clearly continue through the driveway approach; and • The level of the sidewalk should be maintained, and the driveway should be sloped so that the motorist goes up and over the sidewalk.
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From page 155... ...
Traveled Way Design Guidelines 155 lanes, into bicycle lanes, parking lanes or along the sidewalks, thus making it difficult for bicyclists and pedestrians to use the facilities that have been provided for them. Snow and ice blockages can force pedestrians onto the street at a time when walking in the roadway is particularly treacherous.
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From page 156... ...
156 Design Guide for Low-Speed Multimodal Roadways 4.3.4.1 Stormwater Drainage Inlet Design On many roads, stormwater drainage design typically involves a curb and gutter and drainage grates that occur on the right edge of the road, creating potential conflicts with bicyclists. The most effective way to avoid drainage grate problems for bicycles is to eliminate them entirely by using inlets in the curb face.
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From page 157... ...
Traveled Way Design Guidelines 157 typically ride (i.e., within the 6 ft. adjacent to the curb, or between 7 and 12.5 ft.
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From page 158... ...
158 Design Guide for Low-Speed Multimodal Roadways For more detailed information, design guidance and case studies regarding road diets, designers can refer to these sources: • Road Diet Desk Reference (FHWA 2015e) ; • Road Diet Informational Guide (FHWA 2014f)
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From page 159... ...
Traveled Way Design Guidelines 159 4.3.6.3 Traveled Way Design Considerations for Main Streets In designing the traveled way of a main street project, there are three typical elements to consider: speed, width and parking. The pedestrian-oriented nature of main streets means the target speed should be kept low (25–30 mph)
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From page 160... ...
160 Design Guide for Low-Speed Multimodal Roadways 4.3.6.4 Shared and Slow Streets Shared streets (sometimes called flush streets or woonerfs) prioritize pedestrian and bicycle movement by slowing vehicular speeds and communicating clearly through design features that motorists must yield to all other users.
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From page 161... ...
Traveled Way Design Guidelines 161 • Shared street design should use creative means to delineate space for pedestrians with disabilities. This can be done by providing a frontage zone along buildings where a traditional sidewalk is located.
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From page 162... ...
162 Design Guide for Low-Speed Multimodal Roadways make along the route. Designers have a great deal of flexibility when designing bicycle boulevards.
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From page 163... ...
Traveled Way Design Guidelines 163 extensions, turning radius reductions and use of signal timing that discourages high vehicle speeds. In addition, traffic circulation in the surrounding area must be carefully considered before converting streets to one-way.
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From page 164... ...
164 Design Guide for Low-Speed Multimodal Roadways networks. Any connection for use by pedestrians must be accessible to people with disabilities.
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From page 165... ...
Traveled Way Design Guidelines 165 The type, size and design of pedestrian and bicycle facilities along a street or roadway should be carried across the rail tracks such that there is no reduction of service accommodation to those users. In addition, the warning and protection systems used in passive and active crossing systems for vehicles should be designed and operated to serve the non-vehicle users as well.
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From page 166... ...
166 Design Guide for Low-Speed Multimodal Roadways • Two-stage turn queue boxes direct bicyclists to cross rails at a safe angle when turning left across tracks, or turning right across tracks from a left-side bikeway. (Refer to the Urban Bikeway Design Guide [NACTO 2014]
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From page 167... ...
Traveled Way Design Guidelines 167 when the crossing is located near an LRT station, track junction, and/or multiple track alignment involving more than two tracks (Korve et al.
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From page 168... ...
168 Design Guide for Low-Speed Multimodal Roadways warning signs, and/or flashing light signal assemblies. Where LRVs operate using a singletrack, two-way alignment, TCRP Report 17 recommends that an LRV-activated, internally illuminated matrix sign or active, internally illuminated sign with the legend, "TRAIN -- LOOK LEFT/RIGHT" be installed to supplement swing gates (Korve et al.
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From page 169... ...
Traveled Way Design Guidelines 169 • TCRP Report 117: Design, Operation, and Safety of At-Grade Crossings of Exclusive Busways (Eccles and Levinson 2007) ; and • TCRP Report 112/NCHRP Report 562: Improving Pedestrian Safety at Unsignalized Crossings (Fitzpatrick et al.
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From page 170... ...
170 Design Guide for Low-Speed Multimodal Roadways Fire codes may provide additional guidance on emergency access requirements such as minimum traveled way clear widths and minimum space to deploy certain types of equipment, such as ladders, to reach high buildings. The following approaches should be considered in designing traveled ways to accommodate emergency vehicles: • In urban areas with tall buildings, consider placing no-parking zones or staging areas at midblock to accommodate large ladder trucks.
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