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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Suggested Citation:"4. Key Agency Interviews." National Academies of Sciences, Engineering, and Medicine. 2020. Road User Understanding of Bicycle Signal Faces on Traffic Signals. Washington, DC: The National Academies Press. doi: 10.17226/25676.
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Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

CHAPTER 4 Key Agency Interviews The objective of conducting agency interviews was to interview key agency staff to gain insights about the challenges in the design and placement of bicycle signal faces to mitigate road user (driver and bicyclist) confusion. This chapter summarizes the results of these interviews. Methodology and Recruitment The interview protocol was reviewed by the PSU Human Research Protection Program (HRPP) and received an exemption rating (certificate number 196468-18). The research team sent recruiting emails to individuals at agencies that were identified by the inventory with experience with bicycle signal faces. The invitation email included a brief description of the project objectives and a request to schedule a time for the interview that would take between 30 and 60 minutes to complete. Individuals were invited to include others in their organization with expertise who might contribute to the interview. After confirming availability, an email was sent in advance of the interview that included the research objectives, a list of questions and topics, and details of informed consent. The research team asked for consent to record the interview for ease in transcribing the results, and it was noted that the summary results would not be associated with individual names. Persons were notified that they could skip over any question and could let the team know if any answers were to be kept confidential. Following the interview, the research team transcribed the responses to the questions and synthesized the results. The research team interviewed 21 agencies, including six state DOTs, 14 city agencies, and one county, as summarized in Table 9. A number of interviews included multiple professionals at an agency. Due to confidentiality requirements for human subjects as approved by the PSU HRPP, the synthesis does not report the names of those interviewed or associate individuals or agencies with their responses. 49

Table 9. Summary of Interviewed Agencies Agency Name Type Agency Name Type Caltrans State DOT City of Chicago, IL City Delaware DOT State DOT City of Denver, CO City District of Columbia DOT State DOT City of Lincoln, NE City Maryland SHA State DOT City of Minneapolis, MN City Minnesota DOT State DOT City of Seattle, WA City Oregon DOT State DOT Houston Public Works, TX City Hennepin County, MN County Los Angeles DOT, CA City City of Akron, OH City New York City DOT, NY City City of Atlanta, GA City Portland Bureau of Transportation, OR City City of Austin, TX City City San Francisco Municipal Transportation City of Cambridge, MA City Agency, CA Interview Results A summary of the responses for each question is summarized in the following sections. Interviewee Experience Question 1: Please describe how you been involved in the planning, design, construction, operation or maintenance of bicycle signals? Several respondents were involved in multiple phases of the bicycle signal implementation process and/or the group of interviewees provided various perspectives as shown in Table 10. Agencies interviewed ranged from having no signals installed to date to having over 100 signals within their jurisdiction. A majority of the respondents review preliminary or final design plans for bicycle signals. Many respondents are involved in the signal timing and operations of bicycle signals and/or bicycle facilities that require bike-specific timing or phasing elements, even when bicycle signals are not present. Several respondents are also involved in developing or updating existing agency policy or guidance on the use of bicycle signals. Table 10. Respondents Involvement in Bicycle Signals Response # of Agencies* Planning 12 Design 17 Construction 3 Operation 13 Maintenance 5 * Agencies with multiple interviewees and/or staff that was involved in multiple categories were counted in all categories that apply (n=50) 50

Road User Understanding Question 2: Have you received public comments or feedback about driver confusion with the bicycle symbol face? Nearly half of the respondents (48%, n=10) indicated that they have not received or do not know of any comments received from drivers about confusion with the bicycle symbol face, as shown in Table 11. Four interviewees (19%) indicated they have no data due to not having a bicycle signal in place, or other departments or groups within their agency may have additional information. The remaining agencies (33%, n=7) have received feedback from drivers either officially or anecdotally. Two agencies specifically mentioned a learning curve and that after a couple of weeks, reported driver confusion decreased significantly. Two agencies specifically mentioned complaints of the bicycle signal face to be hard to distinguish, particularly at large intersections where the bicycle signal head is placed similarly to the vehicle signal head (e.g., overhead on mast arms). One of those two agencies noted that after the bicycle signal head was relocated slightly further from the vehicle head, reports on confusion dropped. One agency reported significant feedback after the rapid implementation of a two-way bicycle facility which included adding bicycle signals to the existing poles. Feedback from drivers was not specific to the bicycle signals per se but was in response to the overall changes of the roadway operations. As the facility was upgraded with more permanent infrastructure, the bicycle signals were able to be placed on new mast arms directly over the bicycle lane, and complaints have gone away. One agency noted that driver feedback fell into two categories: confusion about what was happening and complaints about the fact that the bicycle signal existed and caused vehicle delay. One agency received only positive feedback from drivers who are happy to know when people on bikes will stop and go. In summary, the consensus from all agencies is that the placement of the bicycle signal is critical to avoiding confusion for drivers. Retrofitting existing signal equipment often requires non-ideal placement due to either limited space or the mast arm being at its weight capacity. Table 11. Public Comments, Driver Confusion Response # of Agencies Yes 7 No *not to the knowledge of 10 interviewee* N/A 4 Question 3: Have you received any public comments or feedback from persons on bicycles about confusion with the bicycle symbol face? Table 12 summarizes the responses received for this question. Three agencies (14%, n=3) either have no bicycle signals installed or other departments/groups within their agency collect user feedback, so it was unavailable for this process. The remaining 18 agencies were split equally between receiving feedback or not. Of the nine agencies that received feedback, all but one (38%, n=8) noted that the feedback was asking for clarification or pointing out confusion related to the operations of the corridor or intersection. One agency has all bicycle signals activated via a pushbutton and received comments related to that. One agency noted they have a large and complex intersection and they use the bicycle signal to assist people on bikes in navigating the 51

intersection. They noted that if it were a more standard intersection, a bicycle signal would not be needed. One agency noted that they have mounted bicycle signals at a lower height in response to feedback at one location where the original placement was too high. One agency noted that they receive questions on how to use a two-stage crossing. The one agency that received comments unrelated to confusion noted that their feedback has all been positive and generally are requests for more bicycle signals. This same agency has received feedback specifically on how helpful the bicycle signals are for riding with children, and requests that more 4-inch near-side signal heads be added at child-height to help navigate more complex intersections. Table 12. Public Comments, Persons on Bicycle Confusion Response # of Agencies Yes 9 No *not to the knowledge of 9 interviewee* N/A 3 Question 4: Please describe your experience (if any) with bicycle-motor vehicle crashes/collisions at intersections with bicycle signals? Over half of the respondents (52%, n=11) were not aware of any crashes or patterns at intersections with bicycle signals, as shown in Table 13. Two of those agencies commented on the fact that official crash datasets are very delayed; often one to four years behind the current year. Three agencies (14%, n=3) were aware of crashes at intersections with bicycle signals, but it was known that they were not related to the bicycle signal in any way and either occurred in a different lane or were due to driver behavior (i.e., running a red light). Two agencies (10%, n=2) are planning future bike signals in response to crash history along a corridor or at an intersection. One agency (5%, n=1) had an intersection with a high crash rate but installed a bicycle signal and is not aware of any subsequent crashes. If there have been any, they were minor and unknown to agency staff. One agency (5%, n=1) had seen crashes after the implementation of a pilot two-way bike facility – primarily due to the driver or person on a bike violating the display indication. Under the previous design, people on bikes had been in the lane and were used to watching the vehicle signal, but with the pilot project are being stopped in their own space, which caused some confusion. That has been addressed with an upgraded design to include mast arms that position vehicle and bicycle displays over the correct lanes and include 4-inch near-side display for increased visibility. Respondents from the remaining three agencies (14%, n=3) either did not have personal experience or knowledge of relevant crash analyses or knew that other departments within their agency had information, but the interviewee did not have access to information on crashes. One agency conducted a protected bike lane study and found that crashes at fully split intersections were higher than expected and that was due to signal violations, which is a behavioral issue more than a confusion issue. Their analysis of the issue is that they have bike signals at places where there is a need for split phasing and the delays become greater leading to non-compliance. 52

Table 13. Experience with Bicycle/Motor Vehicle Crashes Response # of Agencies* No experience, or no data access 3 Not aware of any crashes or patterns 11 Known crash(es) – unrelated to bicycle signal 3 Known crash(es) – design tweaked to mitigate concern 1 Known crash(es) - future bike signal planned in 2 response to crash history Known crash(es) - existing bike signal present in 1 response to crash history Known crash(es) – unknown relation to bicycle signal 1 *One agency had responses that fall under two “Known crash(es)” categories Question 5: Have there been any public education efforts undertaken by your agency for bicycle signals? Just under half of the respondents (43%, n=9) said they are not aware of any public education efforts related to bicycle signals at their agency, as shown in Table 14. Eight agencies (38%, n=8) shared information about public education efforts related to bicycle signals. Of those eight, one is for a planned intersection and was conducted by the consultant; agency staff was not sure if they would be doing additional education after the construction. For all others that have documented education efforts, strategies included informational videos, informational fliers, volunteers/ambassadors on the ground at new facilities, poster boards installed at new facilities, and online websites. Two agencies (10%, n=2) mentioned there might have been educational efforts in the past when bike signals were first implemented in the agency, but that nothing has been done recently. One agency (5%, n=1) did not know. A couple of agencies mentioned they do have education efforts for other bicycle facilities, but nothing specifically geared towards signals. Table 14. Public Education Efforts Response # of Agencies Yes 8 No 10 Not aware of any - possible in past 2 Not Applicable 1 Lens Visibility and Conspicuity Question 6: At some distances and lens display intensity, the bicycle symbol may not be clearly distinguishable from a circular display. Do you think this is an issue that needs more research? Among the 21 agencies interviewed, just over half (53%, n=11) indicated they thought additional research was needed to make bicycle signal symbols more distinguishable from a circular display, as seen in Table 15. Six agencies (29%, n=6) did not believe additional research was needed and the remaining respondents (19%, n=4) indicated they thought it might be, but did not have enough information to form a definitive opinion. Several agencies that indicated there was no need for further research mentioned that they exclusively use 12-inch signal heads for 53

various reasons (agency policy, agency practice, concerns about acquiring/maintaining more than one signal head size). One agency has all bicycle signals mounted horizontally and with a yellow backplate and have seen no issues to date. Two agencies that are in dense urban areas mentioned they don’t think they have issues because their intersections are quite small, but could see the need for additional research based on larger intersections or higher approach speeds. Among agencies that responded in favor of additional research, the following potential topics emerged: • Nearly all mentioned specifically that guidance on the appropriate distance would be most helpful; the research question of interest is: “How far is too far?” • Two agencies shared anecdotes of visibility tests. One mentioned that the NCUTCD committee visited an existing bicycle signal and was not able to distinguish the bicycle symbol from a standard green ball until they were up to the stop line. The other agency set up a bicycle signal in their office and started to lose visibility at about 100 feet away. • One additional agency highlighted the safety concern that when a driver is not able to clearly distinguish their signal from a bicycle signal, the misunderstanding can cause significant safety concerns for all users. • Two agencies specifically noted that guidance on when to use an 8-inch head versus a 12- inch head and when to use far-side, near-side or a combination would be helpful. Table 15. Is Research Needed, Distance Symbol Face Visible Response # of Agencies Yes 11 No 6 Maybe 4 Question 7: It has also been suggested that there could be minor design refinements in the bicycle symbol design for conspicuity that would make it easier to view at a distance. Do you think this is a research need? There were mixed perspectives on the need for further research about possible minor refinements to the bicycle signal symbol design to enhance conspicuity, as shown in Table 16. Among the 21 agencies interviewed, roughly the same number of representatives indicated they thought this was an area in need of further research (38%, n=8) as those that did not (43%, n=9), while approximately one-quarter of respondents (24%, n=5) indicated they thought it might be, but did not have enough information to form a definitive opinion. Notably, in one agency there was disagreement among staff highly knowledgeable in bicycle signal design about the importance of this area for further research, with some staff indicating that the symbol is intuitive as-is, and others indicating that at certain distances and intersection sizes, it may be confused for a green ball by motorists. In all but three agencies, responses to this question were correlated with answers to question 6, indicating that research on the display intensity, distance, and symbol may be valuable to pursue collectively to determine the relative influence of each factor on overall bicycle signal recognition. The lack of consensus on the need for future research on this topic indicates that future research may be beneficial. 54

Table 16. Research Needed, Improved Conspicuity of Symbol Face Response # of Agencies* Yes 8 No 9 Maybe 5 *One agency with multiple interviewees had divergent responses. Question 8: Do you think more research is needed on the selection of lens size (12 inch or 8 inch) of the bicycle signal considering visibility distance? Most respondents (76%, n=16) indicated a desire for additional research on the selection of bicycle signal lens size considering bicycle signal visibility distance, and there was considerable heterogeneity among existing design preferences for different signal sizes, as seen in Table 17. Roughly one-quarter of agencies (24%, n=5) indicated a preference for 12-inch signals based on their experience with motor vehicle signals, and viewed that 8-inch signals may not be as visible from the far side of a large intersection. However, some agencies (14%, n=3) indicated a preference for 8-inch bicycle signals based on the assumption that this size is enough for recognition of a far- side bicycle symbol face, and that the smaller size may help to differentiate bicycle signals from motor vehicle signals and aid road user recognition. Additionally, approximately one-quarter of agencies (24%, n=5) indicated a desire for research on the use of 4-inch near-side signal heads, with some indicating they thought these might be beneficial to use as the primary bicycle signal head since they would be more visible to cyclists if placed close to a cyclist’s path of travel, referencing international examples of the use of this design. Table 17. Research Needed, Selection of Lens Size Response # of Agencies Yes 16 No 3 Spontaneously requested research 5 on near-side use (4”)* *Three respondents also indicated the need for additional research. Question 9: Does your agency use any visibility-restricting devices to shield the bicycle signal faces away from the drivers? Close to two-thirds of agencies (62%, n=13) indicated they did not use any visibility-restricting devices to shield bicycle signal faces, as shown in Table 18. Of the agencies that used them (n=7), close to half (42%, n=3) indicated they only do so in unique circumstances where the potential for confusion of the bicycle and vehicle signal faces was a concern. In these cases, either an irregular intersection geometry or unavoidable proximity of the bicycle signal mounting location to a vehicular signal prompted the decision to use visibility-limiting strategies including louvers or programmable lenses. Among the agencies that indicated they do not use visibility-restricting devices some said they would consider their use in future installations if they felt they were needed. Notably, one agency indicated that they do not think restricting the visibility of a bicycle signal to drivers is a good idea, since they believe a driver should see the signal as a reason they are being held from a conflicting turn movement (i.e., restricted right turn). 55

Table 18. Use of Visibility-Restriction Devices Response # of Agencies Yes 7 No 13 Not Applicable 1 Placement of the Bicycle Signal Face Question 10: Do you have any experience with 4-inch near-side bicycle signal faces? Do you think they improve road user understanding? Have you received positive or negative feedback from bicyclists? Almost two-thirds of respondents (62%, n=13) indicated their agency did not use 4-inch near- side bicycle signal faces, as seen in Table 19. Four agencies (19%) indicated they already use these signals or have a pending installation with a 4-inch near-side signal. Four additional agencies (19%) indicated they are considering using 4-inch near-side signals for future bicycle signal installations or retrofits of existing bicycle signals. Of those agencies that do not use 4-inch near- side signals, this was usually due to the agency’s internal signals policy constraints to require 12- inch heads for all signals, or because the signal shop has not wanted to use a 4-inch signal. All agencies with experience using 4-inch near-side signals indicated they had received positive responses from cyclists, and one noted that they are helpful for persons on a bicycle—especially children—to navigate complex intersections. The lower near-side signal height was highlighted as critical for cyclists who are lower to the ground, such as children and recumbent cyclists. One agency indicated that they had initial concerns about vandalism due to the lower signal height, but that it has not transpired. Overall, feedback indicates that these are very well understood, much appreciated, and facility users would like to see more of them. Table 19. Use of Near-side Four-Inch Bicycle Signal Faces Response # of Agencies Yes, or pending installation 4 No 13 Considering for future installs or retrofits 4 Question 11. What guidelines do you follow for placement of bicycle signal faces and vehicle signal faces when both are visible on the approach? Approximately half of the respondents (52%, n=11) indicated their agency uses the IA-16 as guidance when both bicycle signal and vehicle signal faces are visible on the same approach as seen in Table 20. Less than 25% of respondents cited each of the following guidelines in this instance: MUTCD guidance (19%, n=4), NACTO (10%, n=2), Request to Experiment (RTE) (14%, n=3), State MUTCD (5%, n=1). Three respondents (14%) did not cite a specific source of guidance or indicated they were unsure of what guidance was followed by their agency in this circumstance. Notably, many agencies indicated that they find the requirements of IA-16 to be very restrictive and sometimes difficult to implement. For example, in some cases, the designers stated they were not able to provide three feet of separation between a bicycle signal head and vehicular signal as 56

required by the interim approval, although they try to do so whenever possible. Another agency stated that when considering a new bicycle signal installation, they are faced with the choice of a more seamless process by following the IA-16 requirements or a more arduous process by using an RTE with the design they feel is most appropriate. Table 20. Guidance Used for Placement of Signal Faces Response # of Agencies* IA-16 11 MUTCD 4 Request to Experiment (RTE) 3 None cited/not sure 3 NACTO 2 State MUTCD 1 *Some agencies use more than one source of guidance. Question 12. What other guidelines does your agency follow for bicycle signal placement? Seven agencies (33%, n=7) indicated their agency uses state or local guidance as a supplemental source of signal placement guidance, as seen in Table 21. Aside from state and local guidance, the MUTCD and NACTO guidance were the most commonly cited (19%, n=4, and 14%, n=3, respectively) in the circumstances aside from those prescribed in Question 11. One agency (5%, n=1) indicated it uses the FHWA Separated Bicycle Lane Planning and Design Guide as a supplemental source of guidance, and six agencies (29%, n=6) did not indicate an additional source of guidance. Of those who responded to the follow-up question asking if an agency thinks its placement of bicycle signals is effective, eight of nine agencies (89%) indicated they thought it was effective or stated that they had not received any complaints to the contrary. Table 21. Guidance Used for Signal Placement Response # of Agencies* State/Local Signal Guidance 7 None 6 MUTCD 4 NACTO 3 FHWA Separated Bicycle Lane 1 Planning and Design Guide *Some agencies use more than one source of other guidance. Question 13. Have you studied the motorist or bicyclist compliance of traffic signals based on the placement of bicycle and vehicle signal faces in proximity to each other? A summary of the responses is shown in Table 22. Only four agencies (19%, n=4) indicated they studied bicyclist or motorist compliance based on the placement of the bicycle and vehicle signals in proximity to each other. One jurisdiction studied the difference in compliance between bicycle and vehicle signals placed approximately three and eight feet apart, finding no significant difference in compliance between the two configurations. Another measured if drivers stopped at the stop line or encroached the bicyclist area, and did not observe many violations, but saw some 57

encroachment creating some discomfort. Another informally observed bicyclist signal compliance and found that some comply with the signal, while others do not. Finally, one jurisdiction conducted formal before-and-after studies and found that driver compliance increased when signals were positioned over their lane. Table 22. Study of Compliance Based on Placement Response # of Agencies* Yes 4 No/ Not Applicable /No Response 17 Question 14: What are the design issues or constraints you face for placement of bicycle signal and vehicle signal faces when both are visible on the approach? Except for one, all agencies indicated some design issues or constraints for the placement of the bicycle signal, as seen in Table 23. Over half of the respondents (52%, n=11) mentioned that finding the right location for the bicycle signal face is most difficult. Mast arms often do not have the capacity for an additional signal head and/or sign and pedestal poles often have conflicting existing equipment. A similar concern is the concept of traffic control clutter. Just under half of the respondents (43%, n=9) identified this as a concern related to user misunderstanding as opposed to physical constraints. A quarter of the agencies (24%, n=5) identified right-of-way issues. Under a quarter of the agencies (19%, n=4) mentioned that outdated signal infrastructure is a concern, primarily related to overhead wires (i.e., no mast arms), conduits at capacity in existing equipment, or conduits being inaccessible/degraded and unable to update. Three agencies (14%, n=3) described achieving adequate sight distance as an issue, mainly pointing to placement constraints impacting sight distance. One agency mentioned controller constraints and that they had issues figuring out the conflict monitor and how to add a bike phase to an already eight-phase intersection. One agency mentioned detection being an issue. Table 23. Design Constraints for Placing Bicycle Signal Response # of Agencies* Hard to place 11 Traffic control clutter 9 Not enough right of way (ROW) 5 Outdated signal infrastructure 4 Sight distance 3 Detection 1 Phasing/Controller constraints 1 Unsure 1 * Most agencies mentioned multiple design issues. Question 15: Have you had any challenges in installing the R10-10b “Bicycle Signal” sign with bike signals face? A third of the respondents (33%, n=7) indicated that they had not experienced any challenges with installing the R10-10b bicycle signal sign, as seen in Table 24. Another third (n=6) expressed 58

challenges in installing the sign. Two agencies mentioned issues or concerns about the additional wind load presented by the sign on mast arm installations. Two respondents noted that it was often challenging to find a location for the sign adjacent to the bicycle symbol face. Five of the agencies were not using the sign on most installations. A couple of the respondents expressed the opinion that the sign was redundant to the information provided by the bicycle symbol in the signal face. One agency has developed a design for the sign that incorporates the signal head (similar to a backplate but as a sign). Table 24. Challenges with Installing the R10-10b “Bicycle Signal” Sign Response # of Agencies No challenges with the sign 6 Do not use 8 Challenges* 7 Additional wind load 2 Close enough to the bicycle signal 1 Space / sign clutter / size of sign 2 No specific detail 2 * Some agencies mentioned multiple design issues. Do you think these signs are beneficial? Why or why not? Of the 16 agencies that were asked this follow-up question, five (35%, n=5) agencies indicated that they thought the sign was beneficial, as seen in Table 25. Two agencies clarified their response was for signals without the bicycle symbol in the face. When the bicycle symbol is used in the face, they thought the sign might not be needed. A number of agencies noted that the sign is an additional communication (primarily for motor vehicle drivers), is intuitive and doesn't require that the user recognize the bicycle symbol. However, the majority (57%, n=8) of agencies do not think the sign is necessary/beneficial. One agency noted that if they were not required to use them, they would not to avoid clutter. Two agencies commented that traffic control devices should not need a sign to explain them and generally felt the bicycle symbol signal alone was understood. Table 25. R10-10b Sign Beneficial Response # of Agencies Yes 5 No 8 Maybe / Unsure 1 Operations Question 16: Some jurisdictions make the bike signal housing and/or backplate different from the motor vehicles signals. If you have used this technique, at which locations, and do you think it was effective? There were mixed responses concerning differentiating the bicycle signal housing and/or backplate from the vehicle signals, as shown in Table 26. A third (33%, n=7) of agencies indicated that they had used this approach with some anecdotal success. One agency identified a location 59

where the signal housing and backplate are distinctly different, and while they don't have concrete data, they feel that using a different color makes the bicycle signals stand out. Another agency noted that they have recently implemented this type of design and are collecting data. One agency noted that yellow backplates are the standard in their design guide. Four agencies (n=4) responded that they had not yet tried this technique but were interested in exploring it. More agencies (43%, n=9) indicated they either had not tried this approach or they do not typically use signal backplates. One agency pointed out that the MUTCD requires backplates to be black (i.e., a yellow backplate would be non-compliant). One agency noted that they had placed vehicle signals horizontal and bicycle signals vertical at some intersections (also done with their bus queue jump signal heads). Another noted that they had placed the bicycle signal horizontal and vehicle signals vertical to differentiate them. One agency stated that the more important design feature is that the signal indication is directly overhead the facility it's serving. Finally, one agency commented that it might not be a good idea to make the bicycle signal different as drivers need information from the signals as well. Table 26. Use of Color or Backplate to Distinguish Bicycle Signal Response # of Agencies Yes 7 No 9 Try 4 Not Applicable 1 Question 17: Do you think more research is needed on ways to differentiate bicycle signals from vehicular signal heads? The majority of the agencies (67%, n=14) felt that more research is needed on ways to differentiate bicycle signals from vehicular signal heads. A summary of the responses is shown in Table 27. One agency felt that since the same red-amber-green color indications and signal head frames are used for both vehicular and bicycle signal indications, it would be helpful to identify means to distinguish bicycle heads from others. Agencies felt that it would be helpful to have research that provides definitive guidelines on the signal face, size, and presence of signs. One agency opined that it was very difficult to get the horizontal separation, especially when trying to keep the intersections compact, so there is a need to distinguish the signal heads. A suggestion to use an entirely different color for bicycle signal heads separate from the vehicular signal heads was put forth by one agency. However, another agency noted that maintenance challenges (cost) could arise with the use of two different housings. About 24% of the agencies (n=5) did not think that additional research was warranted. One agency felt that the sign was sufficient for differentiating the vehicular and bicycle traffic signals, while another noted that the lack of complaints/operational issues indicated that more research was not needed. One agency wanted to monitor the installations to determine if additional research was warranted. One agency did not have an opinion. 60

Table 27. Research Needed, Differentiate Bicycle Signals Response # of Agencies Yes 14 No 5 Monitor 1 No opinion 1 Question 18: Has IA-16’s requirement that “bike signals shall be limited to situations where bicycles moving on a green or yellow signal indication in a bicycle signal face are not in conflict with any simultaneous motor vehicle movement” impacted how many bike signals you have installed? Or how you have installed them? A majority (57%, n=12) of the agencies stated that the IA-16’s requirement of limiting bike signals to situations where the bicycles are not in conflict with simultaneous motor vehicle movement had impacted the number of bike signals they have installed, as shown in Table 28. More than one agency stated that there is a need for more flexibility, citing a number of situations where, in their opinion, a bicycle signal could be operated safely and efficiently but not in compliance with IA-16. One agency stated that research on the relative need/safety benefit of this requirement is needed, citing the long delays that result to all users when only movements without conflicts are required. As an example, one agency stated that a compliant design required them to stop all vehicular movements during the bicycle green because a right-turn lane was not present. In addition, some agencies have interpreted the guidance to limit the use of leading bike intervals (LBIs). Other agencies have used the MUTCD RTE process to implement LBIs, delayed turns, or non-exclusive movements that do not comply with the IA-16 requirement. However, 33% (n=7) of the agencies stated that the IA-16 requirement did not impact their installations. These agencies stated that they installed bike signals at locations with exclusive bicycle movements only. Table 28. IA-16 Impacted Installation of Bicycle Signal Faces Response # of Agencies Yes 12 No 7 Not Applicable 2 Question 19: Have you had to restrict vehicles from making certain movements on a bicycle green? If yes, which movements were restricted? Nearly all agencies restrict motor vehicle movements with the bicycle green (86%, n=18), as would be expected with the installation of the bicycle signal, as seen in Table 29. Nearly all of the restrictions involve motor vehicle turns as seen in Table 30. For installations on the two-way bicycle facilities, the left-turn movement is generally restricted. Four agencies mentioned restricting vehicles from making a right turn on red during the bicycle green. For the right-turning movement, several agencies discussed the design considerations of traffic flow and available space when selecting to install a bicycle signal. For lower right-turning volumes, they indicated they might consider a “mixing zone” design over a bicycle signal. 61

Table 29. Vehicle Movements Restricted During Bicycle Green Response # of Agencies Yes 18 No 1 Not Applicable 2 Table 30. Type of Vehicle Movements Restricted Response # of Agencies All movements 2 Turns (Left or Right) 13 Through 1 Are they restricted throughout the phase, or only during a certain portion of the phase? While 33% of the agencies (n=7) stated that they restrict vehicles throughout the bicycle green, 38% of the agencies restricted vehicles only for a part of the bicycle green phase, as shown in Table 31. One agency stated that the part-time restrictions for vehicles are in place only during the lead interval. Table 31. Duration of Phase Vehicle Movements Restricted Response # of Agencies All 7 Part 8 No response 6 Do you use traffic signals, signal arrow faces, signs, or a combination of these to restrict movements? A total of 57% of the agencies stated that they use a combination of traffic signals, signal arrow faces, and signs to restrict vehicle movements, as shown in Table 32. Ten percent of the agencies (n=2) stated that they use arrows only, while 5% of the agencies stated they used signals or signs only (n=1). Twenty-three percent (n=5) of the agencies did not respond to this question. Table 32. Methods for Restricting Vehicle Movements Response # of Agencies Combo 12 Arrows 2 Signals 1 Signs 1 No response 5 62

Question 20: Do you think the person on a bicycle expects to have an exclusive movement on a green bicycle symbol? The opinions of the agencies interviewed were split on whether the person on a bicycle expects to have an exclusive movement on a green bicycle symbol (Yes, n=9; No, n=7). Note that as used here and in the rest of the text, exclusive means “not in conflict with other users” rather than phasing. A summary of the responses is presented in Table 33. One agency thinks that bicyclists expect to have exclusive movement because at most of their installations arrow signals are present on the same mast arm as the bike signal, and the bicyclists are able to view their green indication along with the red indication for vehicles. Another agency stated that bicyclists expect exclusivity because typically people expect that green indication means that they have the right-of-way. Another agency stated that because bicyclists expect exclusive movement, this leads to confusion during the delayed turn (LBI/ Split LBI). One agency has a mix of bike signals, some of which allowed exclusive movements while others did not, so there is no way for the bicyclists to know. Another agency thought that bicyclists interpret the green bicycle symbol as a green ball and therefore do not expect the movement to be exclusive. Three agencies stated that the expectation of exclusivity depended on context. Table 33. Expectation of Persons on Bicycle for Exclusive Movement on Green Bicycle Response # of Agencies Yes 9 No 7 Depends on context 3 Not Applicable / No Response 2 Do you think the person on a bicycle is confused by a green vehicle signal when their bicycle signal face is red? As a follow-up, 28% of the agencies felt that a person on a bicycle would be confused by a green vehicle signal when their bicycle signal face is red, while 43% of the agencies did not think the situation would be confusing, as shown in Table 34. One agency stated that the vehicular green signal could be confusing because bicycles can behave as vehicles if they choose to. Another agency stated that the confusion might not exist if bicycles can see the conflicting movement, but it may lead to confusion if they cannot see the conflicting movement. One agency which thought that the bicyclist would not be confused by the green vehicle signal when their bicycle signal is red stated that the parallel walk indication would frustrate the bicyclists, especially if they have to remain stopped. Table 34. Confusion, Person on Bicycle with Green Bicycle and Red Vehicle Response # of Agencies Yes 6 No 9 Maybe 4 Not Applicable / No Response 2 63

Do you think there are issues with concurrent green vehicle and bicycle signal faces? As a follow-up, the majority of agencies (62%, n=13) did not think there were issues with concurrent green vehicle and bicycle signal faces (responses to this question parallel the opinions on the primary question of exclusive movement). A summary of the responses is shown in Table 35. A number of agencies clarified that as long as there are no conflicting (turning) movements, there would not be any issues. One agency did not see a difference with the green ball and noted at some intersections motor vehicle drivers don’t know if they are facing a split-phase or a permitted left turn. Interestingly, one agency raised an idea that there is a potential for bike signals to be similar to pedestrian signals as a message to turning drivers that bicyclists are present. Table 35. Issues with Concurrent Green Vehicle and Bicycle Signal Faces Response # of Agencies Yes 3 No 13 Depends on context 1 No Response 4 Question 21: What would be the best way to communicate with a person on a bicycle that their movement is permissive or conflicts with other road users? Three agencies stated that they only use bicycle signals with exclusive phases for bikes, so there was currently no need for a permissive display. The remaining agencies expressed a number of design and operational ideas that might be the best way to communicate with a person on a bicycle that their movement is permissive. A flashing yellow bicycle signal (or other variants) was noted by eight agencies as a potential idea, drawing parallels to the flashing yellow arrow display. A combination of the green bicycle symbol and green ball was also noted as a potential option. Signage with a very clear, concise message (e.g., "bicyclists watch for turning vehicles" or “turning bicyclists yield sign”) was suggested. Pavement markings may also be an option. Two agencies stated that there are right-of-way issues implied and that driver education and better awareness of their yielding requirements needs to be part of the solution. Finally, four of the responses indicated that the concept, in general, needs research and that whatever display is used, it needs to be clear to the bicyclists whether they have the right-of-way or whether to expect conflicts. Question 22: Have you or do you plan to use arrows in combination with bike symbols as allowed in IA-16? The majority of agencies (76%, n=16) do not have any plans to use the arrows as allowed in IA- 16 with the bicycle symbol faces, as seen in Table 36. Several agencies were concerned about driver confusion and how to clarify that the arrow is for the bicycle movement and not vehicles. Three agencies noted that they were considering it for a special situation. Two agencies reported using the arrows - one location is an intersection with a one-way street where there is a bike signal on one side of the street, and the other is a connection to a busy campus route. 64

Table 36. Plans to Use Arrows with Bicycle Symbols Response # of Agencies Yes 2 No 16 Maybe 3 Question 23: Are you using yellow change or red clearance intervals for bicycle signal phases? The majority of the agencies (76%, n=16) use both yellow change and red clearance intervals for bicycle signal phases, as seen in Table 37. One agency stated that common complaints are received regarding the green time but never regarding the yellow change or red clearance. One agency stated that they used the additional time for the red intervals to accommodate bicycles but not the yellow, while four agencies did not respond to this question. Table 37. Use of Yellow and Red Clearance Intervals Response # of Agencies Both 16 Red 1 No Response 4 If yes, how are you determining their duration? Do you think that this is an area where additional research is needed? Agencies reported using guidance from the ITE webinars, NACTO Urban Bikeway Design Guide, and AASHTO Guide for the Development of Bicycle Facilities, 2012 Edition (“AASHTO Bike Guide") to determine the duration of these intervals. The number of responses received is shown in Table 38. One agency stated that they used AASHTO guidelines and ended up with very large clearance times. Agencies were fairly evenly split regarding whether additional research was needed for determining yellow change and red clearance durations (Yes, 52%; No, 48%). One agency stated that research should focus on the all-red duration only. Another agency stated that calculations for red clearance might result in time that is not being used, and suggested looking at existing yellow and red intervals and determining if longer intervals do increase safety. Another agency stated the need for additional information on what minimum clearances should be and suggested that local jurisdictions determine how much additional clearance time is needed based on context. Finally, one agency wondered why the 2012 edition of the AASHTO Bike Guide recommends higher duration clearance intervals when bicyclists are detected at a signal, as bicycles are also present at other intersections. Table 38. Research Needed, Signal Timing Guidance Response # of Agencies Yes 11 No Response 10 65

Research Ideas Question 24: Please give us your assessment from 1=low priority to 5=highest priority of the following potential research topics: Appropriate traffic control devices to communicate to a person on a bicycle that their movement is permissive or has conflicts emerged as the top research topic with the highest average score and highest number of five priority rankings, as seen in Table 39. Heterogeneity among existing bicycle signal installations underscores this need. For example, some bicycle signal installations installed under the FHWA Request to Experiment (RTE) process were reported by agency staff to have some form of permissive phasing—and the same is inherently true for an LBI—while those following the guidelines of IA-16 are fully protected for cyclists from conflicting motor vehicle turning movements. Appropriate traffic control devices to communicate allowable movements to a person on a bicycle and guidance on the timing of yellow-change or red-clearance intervals for bicycle signal phases were also highly ranked by the participants. Most participants ranked additional comprehension added by the R10-10b Bicycle Signal sign the lowest. Table 39. Summary of Ranked Potential Research Gaps Number of Average Potential Research Topic “5” Priority Score Rankings g) Appropriate traffic control devices to communicate to a person on a 4.2 11 bicycle that their movement is permissive or has conflicts with vehicles. h) Appropriate traffic control devices to communicate allowable 3.7 6 movements to person on a bicycle. i) Guidance on timing of yellow change or red clearance intervals for 3.6 8 bicycle signal phases. a) Distance and placement where the bicycle symbol may not be clearly 3.5 7 distinguishable from a circular display. d) Design approaches to differentiate bicycle signals from vehicular signal 3.4 2 heads. e) Bicyclist compliance of traffic signals based on the placement of 3.4 5 bicycle and vehicle signal faces in proximity. b) Guidance on visibility distance and road user comprehension by lens 3.3 5 sizes. c) Minor design refinements in the bicycle symbol design for conspicuity. 2.5 1 f) Additional comprehension added by the R10-10b “Bicycle Signal” sign. 2.4 1 Question 25: Are there any other areas related to bicycle signals that you think need additional research or issues we should know about? Agencies suggested several additional topics related to bicycle signals not already addressed in the questions: • Feasibility and best practice of louvered bicycle signals. • Guidance on bicycle detection and feedback confirmation. • Guidance on LBIs and how best to communicate to the bicyclist to use the lead interval. • Maintenance aspects of bicycle signals. 66

• Thresholds for bicycle signal warrants and associated criteria. • Criteria for the use of near-side 4-inch indication and associated benefits (if any). • Guidance on the number of bicycle signal heads (is one indication sufficient?). • Guidance on signal timing (including minimum green), phasing, and progression techniques. • Techniques for driver education and inclusion of bicycle-focused educational material in driver licensing materials. Summary The interview questionnaire consisted of 25 questions that were divided into six categories. These categories included questions on experience with bicycle signals, road user understanding, lens visibility and conspicuity, placement of the bicycle signal face, operations, and research ideas. A number of clear trends emerged from the interviews as potential research gaps (not all related to road user understanding): • Placement of bicycle signals in relation to the driver line of sight. • Guidance on appropriate distance for visibility when using a bicycle signal with a bicycle symbol face in the lens. • Refinement of the specifications for display intensity and symbol design. • Guidance on selection of lens size considering visibility distance, including 4-inch near-side signal heads. • Techniques to differentiate the bicycle signal from motor vehicle signal heads. • Tradeoffs associated with signal timing and phasing strategies for bicycles (exclusive phasing, LBI, delayed turn). • Guidance on ways to communicate with a person on a bicycle that their movement is protected or permissive and conflicts with other road users. • Examining current guidelines for yellow change and red clearance and determining if longer intervals increase safety. 67

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Road User Understanding of Bicycle Signal Faces on Traffic Signals Get This Book
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Prior to 2013, the use of bicycle-specific signals in the U.S. was limited to a few jurisdictions. However, in recent years, the number of installations has grown rapidly. This research identified more than 500 intersections using bicycle signals in a variety of contexts.

Despite the recent approval and practice, the TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 273: Road User Understanding of Bicycle Signal Faces on Traffic Signals explores the questions that remain regarding road-user understanding of bicycle signals.

The objective of this research was to summarize and synthesize the U.S. experience with bicycle signal installations to identify any remaining gaps in understanding road-user comprehension and compliance with bicycle signals that could be effectively addressed through further research.

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