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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
×
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
×
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
×
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
×
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
×
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Suggested Citation:"Chapter 2: State of the Practice." National Academies of Sciences, Engineering, and Medicine. 2018. Assessing Interactions Between Access Management Treatments and Multimodal Users. Washington, DC: The National Academies Press. doi: 10.17226/25344.
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5 C H A P T E R 2 : S T A T E O F T H E P R A C T I C E State of the Practice Introduction This chapter summarizes the state of the practice related to the effects of access management (AM) treatments on the safety and operation of the pedestrian, bicycle, transit, or truck travel modes. The first section describes the findings related to a review of the literature. The second section describes the findings from an agency survey on the topics related to commonly used AM techniques and their effect on multimodal users. Literature Review Overview of Process This section summarizes the literature review conducted during the research project. The review was conducted in three stages. During the first stage, a large number of resource documents were reviewed that address AM techniques commonly used to reduce or eliminate conflicts between motor vehicles and non-auto roadway users. The objective of this review was to (1) identify AM techniques being used and (2) characterize the expected effect of each technique on the safety or operation of motor vehicles, pedestrians, bicyclists, transit riders, and trucks. The focus of this portion of the review was on authoritative reference documents. More than 70 AM techniques were identified during this review. The key findings from the first-stage review are summarized in the next section. Detailed findings from this review are documented in Appendix A. During the second stage of the review process, the literature review focused on 20 AM techniques that had been identified as potential candidates for further study during Phase 2 of the project. The objective of this review was to identify the existence of published quantitative relationships that can be used to predict the effect of a technique on the performance of the pedestrian, bicycle, transit, or truck travel mode. Techniques of interest could affect performance through either of the following cases: (1) the AM technique (e.g., add turn bay) is installed at the location of interest, or (2) a change in roadway design (e.g., offset turn bay) or traffic control is provided for the purpose of improving the access management function. The focus of this portion of the review was on authoritative reference documents and research publications. The findings from this review are also documented in Appendix A. During the third stage of the review process, additional research publications were reviewed that related to the AM techniques that had been selected for field study. The objective of this review was to identify traffic characteristics and design elements that may have an effect on pedestrian, bicycle, transit, or truck safety or operation. The findings from this review were used to develop the final study designs. The findings from this review are documented in Appendix E.

6 Key Findings This section summarizes the key findings from the first-stage literature review. Appendix A provides a list of documents that were reviewed. Table 3 lists the techniques that were identified during the literature review. For each technique, columns 2 through 9 summarize a key finding from the literature review regarding the documented influence of the technique on the operation or safety of the pedestrian, bicycle, transit, and truck modes. The word “Yes” is shown if one or more studies were identified that quantified the effect of the technique on the corresponding travel mode. The word “Trend” is used to indicate that the only studies found were those that used qualitative terms to describe the effect of a technique. The word “Possible” is used to indicate those combinations for which no information was found in the literature review but experience indicates some effect is possible. The word “No” is used to identify those combinations for which no information was found and experience indicates an effect is unlikely or negligible. Table 3. Technique influence on operations and safety. Technique (listed by ID code1) Does Technique Implementation have an Effect on...3 Appli- cation Scale Data Source the Operation (or LOS) of... the Safety of... Pe de st ria n B ik e Tr an si t Tr uc k Pe de st ria n B ik e Tr an si t Tr uc k O pe ra tio ns Sa fe ty Primary Techniques Identified in NCHRP Report 420 1a. Establish traffic signal spacing criteria Yes Yes Trend Pos- sible Trend Trend Pos- sible Pos- sible Corridor Simula- tion Crash Reports 1b. Establish spacing for unsignalized access Trend Yes Trend Pos- sible Yes Trend Pos- sible Pos- sible Corridor Simula- tion Simula- tion 1c. Establish corner clearance criteria No No Pos- sible Pos- sible No No Pos- sible Pos- sible Site Simula- tion Crash Reports 1d. Establish access separation distances at interchanges Trend Trend Trend Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Crash Reports 2a.& 2b. Install non-traversable median on undivided highway and replace TWLTL with non-traversable median Yes Trend Yes Pos- sible Yes Yes Pos- sible Pos- sible Corridor Simula- tion Crash Reports 2c. Close existing median openings Trend Trend Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor Simula- tion Crash Reports 2d. Replace full median opening with median designed for left turns from the major roadway Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion 3a. Install left-turn deceleration lanes where none exists Trend Trend Trend Yes Pos- sible Pos- sible Pos- sible Yes Site Simula- tion Simula- tion 3b. Install left-turn acceleration lane at unsignalized intersection Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field 3c. Install continuous two-way left-turn lane on undivided highway Yes Pos- sible Yes Pos- sible Yes Pos- sible Pos- sible Pos- sible Corridor Simula- tion Crash Reports 3d. Install U-turns as an alternative to direct left turns Pos- sible Pos- sible Pos- sible Yes Pos- sible Pos- sible Pos- sible Pos- sible Corridor Simula- tion Simula- tion 3e. Install jug handle and eliminate left turns along highways Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion 4a. Install right-turn deceleration lane or right-turn lane Yes Trend Trend Trend Yes Yes Pos- sible Trend Site Simula- tion Simula- tion

7 Technique (listed by ID code1) Does Technique Implementation have an Effect on...3 Appli- cation Scale Data Source the Operation (or LOS) of... the Safety of... Pe de st ria n B ik e Tr an si t Tr uc k Pe de st ria n B ik e Tr an si t Tr uc k O pe ra tio ns Sa fe ty 4b. Install continuous right-turn lane Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Crash Reports 5a. Consolidate driveways Yes Trend No Pos- sible Trend Trend No Pos- sible Corridor Simula- tion Simula- tion 5b. Channelize driveways to discourage or prohibit left turns on undivided highways Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Simula- tion 5c. Install barrier to prevent uncontrolled access along property frontage Yes Trend Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor or Site Field Crash Reports 5d. Coordinate driveways on opposite sides of street Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field 6a. Install frontage road to provide access to individual parcels Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor Simula- tion Crash Reports 6b. Locate/relocate the intersection of a parallel frontage road and a crossroad farther from the arterial–crossroad intersection Yes Yes Yes Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Crash Reports Selected Other Techniques Identified in NCHRP Report 420 B-1 Interchanges B-1-1 Build interchange (at major intersection or activity center). Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Crash Reports B-1-2 Modify freeway ramps to improve access. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-1-3 Build freeway frontage road. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor Simula- tion Crash Reports B-2 Frontage Roads B-2-2 Construct a bypass road. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible System or Corridor Simula- tion Crash Reports B-2-3 Build a reverse frontage road (i.e., Backage Road). Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor Simula- tion Crash Reports B-3 Medians - Left Turns B-3-1 Install median barrier with no direct left-turn ingress or egress. Yes Pos- sible Pos- sible Pos- sible Pos- sible Yes Pos- sible Pos- sible Site Simula- tion Simula- tion B-3-7 Install channelizing islands to prevent left-turn deceleration lane vehicles from returning to through lanes. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-3-8 Install median channelization to control the merge of left-turn egress vehicles. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-3-12 Install alternating left-turn lane. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor Field Crash Reports B-3-13 Install isolated median and deceleration lane to shadow and store left-turning vehicles. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion

8 Technique (listed by ID code1) Does Technique Implementation have an Effect on...3 Appli- cation Scale Data Source the Operation (or LOS) of... the Safety of... Pe de st ria n B ik e Tr an si t Tr uc k Pe de st ria n B ik e Tr an si t Tr uc k O pe ra tio ns Sa fe ty B-3-14 Install left-turn deceleration lane in lieu of right-angle crossover. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-3-15 Install median storage for left- turn egress vehicles. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-3-16 Increase storage capacity of existing left-turn deceleration lane. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-3-17 Channelize left-turn lanes across wide medians. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-3-20 Construct flyover to accommodate left-turn egress/and ingress movements. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-3-21 Prohibit left turns. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor or Site Field Reports or sim B-3-22 Build left-turn connecting roads. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor or Site Simula- tion Crash Reports B-4 Right Turns B-4-5 Install channelizing islands to move ingress merge point laterally away from the highway. Yes Yes Pos- sible Trend Yes Yes Pos- sible Trend Site Simula- tion Simula- tion B-4-6 Move sidewalk–driveway crossing laterally away from highway. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-5 Access/Driveway Location – Retrofit Consolidation B-5-1-2 Consolidate existing access whenever separate parcels are assembled under one purpose, plan, entity, or usage. Pos- sible Yes Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-5-2-1 Encourage connections between adjacent properties (even when each has highway access). Trend Trend Trend Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Not amen- able to analysis -- -- B-5-2-2 Require access on collector street (when available) in lieu of additional driveway on highway. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-5-2-3 Relocate or reorient access. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion Relocation B-5-3-2 Locate a new driveway opposite an intersection or driveway and install a traffic signal where warranted and properly spaced. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-5-3-3 Install two one-way driveways in lieu of one two-way driveway. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-5-3-4 Install two two-way driveways with limited turns in lieu of one standard two-way driveway. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-5-3-5 Install two one-way driveways in lieu of two two-way driveways. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field

9 Technique (listed by ID code1) Does Technique Implementation have an Effect on...3 Appli- cation Scale Data Source the Operation (or LOS) of... the Safety of... Pe de st ria n B ik e Tr an si t Tr uc k Pe de st ria n B ik e Tr an si t Tr uc k O pe ra tio ns Sa fe ty B-5-3-6 Install two two-way driveways with limited turns in lieu of two standard two-way driveways. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-6 Traffic Controls B-6-1 Install traffic signal at high-volume driveways. Yes Yes Yes Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Crash Reports B-6-2 Install traffic signals to manage traffic flow and meter traffic for larger gaps. Trend Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Crash Reports B-6-3 Restrict parking on the roadway next to driveways to increase driveway turning speeds. Trend Pos- sible No No Trend Pos- sible No No Corridor or Site Simula- tion Crash Reports B-6-4 Provide reversible operation of access drive. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-6-5 Implement curbside loading controls. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor Field Crash Reports B-6-6 Prohibit left-turn driveway maneuvers on an undivided highway. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor Field Crash Reports B-6-7 Install one-way operations on the highway. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible System or Corridor Simula- tion Crash Reports B-6-8 Rep lace parallel on-street parking with off-street parking. Yes Yes Yes Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Corridor Simula- tion Crash Reports B-6-10 Install roundabout2 Yes Yes Yes Pos- sible Trend Pos- sible Pos- sible Pos- sible Site Simula- tion Simula- tion B-7 Access/Driveway Design Install driveways with the appropriate return radii, throat width, and throat length for the type of traffic to be served2 Trend Trend Trend Trend Trend Trend Pos- sible Pos- sible Site Simula- tion Simula- tion B-7-1 Widen right through lane to limit right-turn encroachment onto the adjacent lane to the left. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-7-6 Install driveway channelizing island to prevent left-turn driveway encroachments conflicts. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-7-7 Install driveway channelizing island to prevent right-turn deceleration lane vehicles from returning to the through lanes. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-7-8 Install driveway channelizing island to control the merge area of right- turn egress vehicles. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-7-9 Regulate the maximum width of driveways, B-7-23 widen driveways to improve storage Trend Pos- sible No Pos- sible Pos- sible Pos- sible No Pos- sible Not amen- able to analysis -- -- B-7-10 Install visual cues of the driveway. Trend Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Not amen- able to analysis -- --

10 Technique (listed by ID code1) Does Technique Implementation have an Effect on...3 Appli- cation Scale Data Source the Operation (or LOS) of... the Safety of... Pe de st ria n B ik e Tr an si t Tr uc k Pe de st ria n B ik e Tr an si t Tr uc k O pe ra tio ns Sa fe ty B-7-11 Improve driveway sight distance and B-7-12 Regulate minimum sight distance Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-7-13 Optimize sight distance in the permit authorization stage. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Not amen- able to analysis -- -- B-7-14 Increase the effective approach width of the driveway (horizontal geometrics). Trend Trend Trend Trend No No Pos- sible Pos- sible Site Field Field B-7-15 Improve the vertical geometrics of the driveway. Trend Trend Trend Trend No No Pos- sible Pos- sible Site Field Field B-7-16 Increase the turning speed of right-angle median crossovers by increasing the effective approach width. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Site Field Field B-7-17 Install additional exit lane on driveway. Pos- sible Pos- sible No Pos- sible Pos- sible Pos- sible No Pos- sible Site Simula- tion Simula- tion B-7-18 Require two-way driveway operation where internal circulation is not available. Pos- sible Pos- sible No Pos- sible Pos- sible Pos- sible No Pos- sible Site Field Field B-7-19 Control driveway design elements. Trend Trend Trend Trend Pos- sible Pos- sible Pos- sible Pos- sible Not amen- able to analysis -- -- B-7-21 Provide full driveway access with steady flow in one direction of travel on arterial road. Pos- sible Pos- sible No Pos- sible Pos- sible Pos- sible No Pos- sible Not amen- able to analysis -- -- B-7-22 Design driveways so signals impact only one side of artery at any one location. Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Pos- sible Not amen- able to analysis -- -- Notes: 1 – Technique ID codes are referenced to NCHRP Report 420 (Gluck et al., 1999). 2 – Technique added or modified by the NCHRP 03-120 research team. 3 – Treatment effect indicators: “Yes” documented quantitative effect; “Trend” documented qualitative effect (but no documented quantitative effect); “Possible” no study found but possible effect; and “No” effect is unlikely or negligible. Column 10 of Table 3 indicates the application scale, which is discussed in Chapter 3. For a few techniques, this column indicates that the technique is not amenable to analysis. This determination was made when the technique description was not specific about the change made to the roadway, the specified change is not within the direct control of the public agency, or the data needed to evaluate the technique effect on performance could not be reasonably collected. The information in columns 11 and 12 of the table is also discussed in Chapter 3. Each technique in Table 3 has eight associated combinations of travel mode and performance measure category (i.e., pedestrian safety, bike safety, transit safety, truck safety, pedestrian operation, bike operation, transit operation, and truck operation). The table shows all 592 possible performance relationships (= 74 techniques × 2 performance categories × 4 travel modes), where one table cell represents one performance relationship. The information provided in columns 2 through 9 of this table

11 indicates which of the relationships are documented in the literature, which are undocumented but may be developed through research, and which are undocumented and unlikely to exist. About 550 of the 592 relationships shown in the table are identified as “undocumented but may be developed through research” and, as such, were candidates for development in Phase 2 of the research project. Agency Survey This section documents the methodology for, and summarizes the findings from, a national survey of multimodal access management needs and practices. The purpose of the survey was to identify multimodal access management interactions and to guide the research team and panel in selecting interactions to evaluate in greater detail. A range of information regarding access management interactions was gathered via the survey from practitioners and researchers from various agencies, institutions and modal backgrounds. The survey instrument is described in Appendix B. Overview of Process The survey instrument was developed using a list of traditional access management treatments as categorized in NCHRP Report 420 (Gluck et al., 1999) and updated by the research team. The full list of access management treatments was grouped into general categories (e.g., non-traversable medians) and subsequently refined to reflect the most frequently used traditional access management treatments. Respondents were provided information on subtreatments pertinent to each category of treatments by hovering over each item in the online survey form. The following list identifies the subtreatments applicable to a given treatment: 1. Install non-traversable medians (a) Install non-traversable median on undivided highway; (b) Replace two-way left-turn lane with non-traversable median; (c) Install isolated median barriers. 2. Manage the location, spacing and design of median openings (a) Regulate median opening spacing; (b) Close existing median openings; (c) Replace full median opening with median designed for left turns from the major roadway; (d) Install U-turns as an alternative to direct left turns. 3. Manage spacing of traffic signals (a) Establish traffic signal spacing criteria. 4. Manage location and spacing of unsignalized access (a) Establish spacing for unsignalized access (e.g., driveways); (b) Establish corner clearance criteria; (c) Locate/relocate the intersection of a parallel frontage road and a crossroad farther from the arterial–crossroad intersection; (d) Require access on collector street (when available) in lieu of direct on highway; (e) Relocate or reorient access as part of roadway reconstruction. 5. Consolidate driveways (a) Consolidate existing access whenever separate parcels are assembled under one purpose, plan, entity, or usage; (b) Consolidate driveways during roadway projects.

12 6. Manage the spacing of signalized and unsignalized access on crossroads in the vicinity of freeway interchanges [no subtreatments]. 7. Install continuous two-way left-turn lane on undivided highway (non-road diet scenarios) [no subtreatments]. 8. Install left-turn lanes (a) Install left-turn deceleration lanes at roadway intersections; (b) Install left-turn deceleration lanes at median openings; (c) Increase storage capacity of existing left-turn deceleration lane; (d) Install alternating left-turn lane. 9. Install right-turn lanes (a) Install right-turn deceleration lane at roadway intersections; (b) Install right-turn deceleration lane at site driveways. 10. Control driveway design elements (a) Require design of driveways with the appropriate return radii, throat width, channelization, number of lanes and throat length for the type of traffic to be served; (b) Channelize driveways to discourage or prohibit left turns on undivided highways and to guide ingress/egress movements; (c) Improve the vertical geometrics of the driveway; (d) Install barrier to prevent uncontrolled access along property frontage; (e) Install visual cues of the driveway. 11. Provide adequate sight distance at access points [no subtreatments]. 12. Manage the location and placement of parking (a) Replace curb parking with off-street parking; (b) Restrict parking on the roadway in the vicinity of driveways to improve sight distance. 13. Install roundabout (a) Install roundabout at roadway intersection; (b) Install roundabout at interchange. 14. Install service or frontage roads o (a) Install frontage road to provide access to individual parcels; o (b) Install rear service road to provide access to individual parcels. 15. Improve supporting network o (a) Connect existing street networks to relieve primary roadway; o (b) Encourage connections between adjacent properties. 16. Other [completed by respondent]. The survey was administered electronically to specific individuals by using survey links unique to the individual’s email address. The use of unique survey links allowed the survey to be completed collaboratively and forwarded to any personnel within an agency wishing to participate. It also allowed the research team to monitor survey completion. Follow-up messages were sent via the individualized links to encourage survey participation or completion of partially completed surveys. A second survey was distributed via a general link not specific to any individual that could be widely disseminated via email. This link provided a way to reach out to the broader population of planners, engineers, and modal agencies who might be interested in participating. Efforts were made to disseminate the electronic survey links to: (a) executive directors of metropolitan planning organizations (MPOs) known to engage in access management plans and projects (based on a review of the literature); (b) state transportation agency access management and/or research contacts; (c) TRB Access Management Committee, Highway Capacity and Quality of Service Committee, Highway Safety Performance Committee, Roadway Safety Culture Subcommittee, Bus Transit Systems

13 Committee; Transit Capacity and Quality of Service Committee, Bicycle Transportation Committee, and Pedestrian Committee contacts; and (d) the broader community of transportation planners and engineers. Stakeholder groups were not directly surveyed; rather, agencies were queried as to the perspectives of stakeholder groups relative to their projects. In addition, the survey was sent to selected individuals with known expertise in planning and design of transportation projects for non-auto modes. The research team sought the cooperation of the AASHTO Standing Committee on Research (SCOR), Association of Metropolitan Planning Organizations (AMPO), National Association of Regional Councils (NARC), Institute of Transportation Engineers (ITE), the National Association of County Engineers (NACE), the National Association of City Transportation Officials (NACTO), and the American Planning Association’s (APA) Transportation Planning Division, as well as the chairs of the aforementioned TRB Committees and subcommittees, to reach the appropriate contacts within transportation agencies and to identify practitioners across the country. Some organizations provided email distribution lists, so that the survey completion could be shared among participants within agencies or organizations and adequately monitored. Others disseminated the general link via their newsletters and websites or forwarded the general link to specific individuals within their agency. Respondents were instructed that questions referring to “your agency or organization” were intended to target state, regional, and local government staff and consultants that work on roadway plans and projects. Given the cross-functional nature of the survey and diversity of potential respondents, those not identifying as one of the aforementioned groups were advised to respond based upon their observations, experience, or research in relation to the identified access management treatments. This latter group included transit agency staff, bicycle and pedestrian planners, non-profit organizations, and university researchers. Survey results were reviewed and summarized in written, tabular, and chart form. Observations from participants on interactions between access management treatments and multimodal users are noted below, along with strategies that have been used to address adverse interactions, analysis techniques, and analysis needs and priorities relative to the interaction between access management treatments and modal users. Survey Findings The researchers surveyed practitioners and researchers from various agencies and institutions in the U.S. The survey was used to identify the AM techniques typically used by agencies. It was also used to gather the respondent’s opinion on the effect of various AM techniques on the safety or operation of the non-auto travel modes. Finally, the survey was used to identify agency needs and priorities for information describing the effect of specific AM techniques on the safety or operation of the non-auto modes. A total of 381 individuals responded to the survey, with the majority (75.8%) identifying as consultants (27.3%), state transportation agency staff (27.0%), or university transportation researchers (21.5%). Respondents were presented with a list of traditional AM techniques and queried as to which of the techniques their agency or organization uses to improve transportation system performance. Techniques used or advanced by a majority of these respondents are identified in the following list:  Manage the location, spacing and design of median openings (64.5%);  Install or modify left-turn lanes (63.9%);  Install roundabouts (62%);  Manage location and spacing of unsignalized access (62%);  Provide adequate sight distance at access points (61.7%);  Install non-traversable medians (61.7%);

14  Install right-turn lanes (58.9%);  Manage spacing of traffic signals (57.9%);  Consolidate driveways (56.7%); and  Control driveway design elements (53.3%). The top AM techniques identified as needing additional analysis (with regard to their interaction with the safety and/or operational performance of non-auto modes) across all respondents are identified in the following list:  Manage spacing of traffic signals (25%);  Install non-traversable medians (24%);  Manage the location and spacing of unsignalized access (24%); and  Install roundabout (24%). A detailed compilation of the survey findings is provided in Appendix B. References Gluck, J., H. Levinson, and V. Stover. (1999). NCHRP Report 420: Impacts of Access Management Techniques. TRB, National Research Council, Washington, D.C.

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TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 256: Assessing Interactions Between Access Management Treatments and Multimodal Users describes operational and safety relationships between access management techniques and the automobile, pedestrian, bicycle, public transit, and truck modes. This contractor's report may help assist in the selection of alternative access management techniques based on the safety and operation performance of each affected travel mode.The roadway system must accommodate many types of users—bicyclists, passenger cars, pedestrians, transit, and trucks. This report examines the interactions between multimodal operations and access management techniques and treatments, and the trade-off decisions that are necessary.

NCHRP Research Report 900: Guide for the Analysis of Multimodal Corridor Access Management accompanies this report.

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