CHAPTER 4

Practitioner Interviews

The research team interviewed 16 people representing 10 city agencies (including the District of Columbia), three state DOTs, two counties, and NACTO as part of the interview effort. The objectives of the interviews were to understand how practitioners are making design decisions today, learn about typical challenges they encounter, and determine what additional research would help their future decision-making and design processes. The interview protocol and procedures were reviewed by Portland State University’s Human Research Protection Program Institutional Review Board and received an exempt status (Protocol #217169-18).

The information gathered from the interviews provides insight into how practitioners and agencies identify design and safety challenges at intersections with bike lanes, and how practitioners evaluate and identify design treatments to implement at intersections. The interviews also provide information on topic areas where practitioners lack research or guidance on design treatments.

Methodology

The research team interviewed practitioners from a variety of settings to increase our ability to capture the full range of issues that practitioners face. To ensure diverse participation and representation of issues, practitioners with diverse roles and skills, representing a range of agencies and geographical contexts were selected for the interviews.

Table 6 shows the 16 agencies and jurisdictions that responded in time to complete the interviews. Each interview included participation from at least one planner or engineer from each agency and if more than one representative was interviewed, the comments from the interviewees were synthesized and reported to reflect the response from the agency or jurisdiction.

The research team asked the interview participants questions related to seven themes:

• Practitioner role and experience with selecting and designing treatments for separated bike lanes at intersections
• Guidance, standards, policies, and overarching frameworks
• Factors that influence treatment selection
• Preferred design treatments
• Research gaps or interests
• Safety analysis
• Data availability and sites for analysis

More details about the interview protocol, including a full list of interview questions, are in the Appendix B. The following section summarizes the overall themes distilled from the interviews.

Interview Results

This section describes the results of the interviews with transportation professionals regarding their experience selecting, installing, and evaluating bikeway design treatments at intersections. Results are presented in terms of the seven themes.

The results are reported in terms of trends identified across all agencies. The project team reviewed responses to all questions by agency type (e.g., city, county, or state) but did not identify any discernable trends. This may be due to the small sample size of county and state agencies.

Practitioner Role and Experience

Interviewees included a combination of planners and engineers - 52 percent planners and 48 percent engineers. Several interviewees manage their agency’s bicycle capital projects programs or lead bike master planning and Complete Streets projects. All hold positions as either program coordinators, project managers, senior or principal engineers/planners, or department directors. Interviewees from 13 of the 16 agencies specifically mentioned having experience selecting bikeway treatments for intersections, although most have more experience with general bikeway planning and design than specifically with separated bike lanes. Most interviewees have experience managing separated bike lane projects and all interviewees have experience designing or selecting separated bike lane treatments in some capacity. Interviewees from four agencies also noted that they have experience in evaluating treatment effectiveness. As a whole, interviewees had a comprehensive understanding of planning, designing, installing, and maintaining separated bike lane treatments at intersections. All 13 of the interviewees who rated their level of experience with separated bike lane planning and design indicated that they had either moderate or extensive experience; none rated themselves as having minimal experience.

Guidance, Standards, Policies, and Overarching Frameworks

Guidance and Standards

All interviewees indicated that their agencies review national guidance when determining which treatments to install (see Table 7). The most commonly cited source of national design guidance was NACTO, followed by AASHTO. One agency noted that NACTO’s graphics are very helpful, but they do not always provide enough detailed design guidance for all treatments. These comments suggest that additional guidance is needed to support engineers in the design and installation of bicycle treatments, particularly newer treatments. Many jurisdictions (e.g., Montgomery County, MD) also noted that they use

MassDOT’s Separated Bike Lane Planning and Design Guide, and for some, this is the only guidance they use for specific separated bike lane design questions.

Seattle, Montgomery County (MD), Minnesota DOT, and Massachusetts DOT have their own adopted state or local design guidance. One other agency is in the process of developing its own guidance, and two others have their own design standards, but mostly follow outside guidance. Some agencies also refer to design guidance developed by other local or state agencies, such as the District of Columbia DOT and the City and County of Denver, who use Montgomery County’s bicycle design guidance. A few interviewees also mentioned that they often call staff from other cities to discuss design questions. Staff from 14 of the 16 agencies indicated that they refer to multiple design guides when selecting intersection treatments; there is not one guide that meets all of their needs.

Only one interviewee specifically mentioned using TRB/NCHRP research papers and reports in addition to design guides, however, several other interviewees mentioned that they generally try to stay up to date with the latest research. Some agency staff want to see the data on a treatment first, conversely others are more open to experimenting with new treatments and will install treatments as pilot projects while national research and/or guidance are still under development.

Policies and Overarching Frameworks

Several of the agencies interviewed have overarching policies or frameworks that influence their design decisions (Table 7). Vision Zero or statewide Towards Zero Deaths initiatives were the most commonly identified frameworks. Thirteen out of the 16 agencies interviewed have Vision Zero or Towards Zero Deaths policies. Although none of these policies dictate where to install treatments or which treatments to install, they do make pedestrian and bicycle safety a priority. A few agencies prioritize installing treatments or treatments with greater separation between roadway users at locations along their local high injury network.

Several agencies, including Madison, Bellingham, Seattle, and Michigan DOT noted that their Complete Streets policies influence their decision-making framework. One agency also mentioned that it has a strict Green Streets policy that can limit the types of bikeway design treatments that can be used in some locations. Although there were not formal policies, two agencies noted that they focus on providing a network for people of all ages and abilities and this framework influences their decision about where to install protected bikeways and intersection treatments that separate drivers from bicyclists.

Table 7. Agency Use of Design Guidance and Overarching Frameworks

Note: Values in this table are based on responses from 16 agencies.

Treatment Selection

Interviewees discussed the factors they consider to be most relevant when selecting intersection treatments, as well as common design issues and constraints. Interviewees indicated that they consider local roadway and land use context, safety, and volumes when deciding which treatment to install. They also consider feasibility, including width of right-of-way, cost, stakeholder support, and age or capacity of existing signal infrastructure.

Table 8 lists the different factors agency staff use to select separated bike lane treatments at intersections. The most commonly identified factors across all agencies are pedestrian volume, vehicle speed (posted or measured), turning motor vehicle volume, and anticipated bicycle volume. Fifteen out of the 16 agencies interviewed consider pedestrian volume when selecting separated bike lane treatments for intersections. Note that it is possible that this factor was mentioned the most frequently because it was the only factor that interviewees were specifically asked about during the interview; all other factors were solicited through open-ended questions.

Overall, interviewees noted interest in and concerns with turning vehicle speeds and minimizing conflict points between drivers and bicyclists. One agency representative noted that if the goal for the bikeway is safety and comfort, the three key factors used to determine the appropriate treatment are turning vehicles, motorist speed, and vehicle volume. They remarked that since agencies have limited control over volume, the aim should shift to controlling the speed, or at least the turning speed, of vehicles. If speed cannot be managed, separation between drivers and bicyclists through space and time becomes that goal.

Snow is an important consideration for agencies that have frequent snow events in the winter, and some of these agencies expressed an interest in more specific design guidance for communities that must deal with snow piles and plowing. Snow and concerns related to snowplows and facility maintenance place additional design constraints on agencies. For example, agencies may want to install corner islands and offset crossings or other treatments to slow turning vehicle speeds, but they are limited by only being able to install treatments that a snowplow can easily navigate.

Table 8. Factors agencies consider to select design treatments

Note: Values in this table are based on responses from 16 agencies. All factors listed above were identified through open-ended responses, except for pedestrian volume, which interviewees were specifically asked about. When respondents were first asked to list the factors they consider when selecting design treatments, six listed pedestrian volumes, compared to the 15 who indicated that they considered pedestrian volume when specifically asked about this factor.

*Includes posted speed, travel speed if available, or turning vehicle speed

**May include turning bicycle volume

Thresholds

Interviewees were also asked whether they have any set thresholds for the factors they use to select treatments. Half of the 16 agencies interviewed do not have specific thresholds and rely on engineering judgement and past experience. Three agencies noted that although thresholds can be useful, they would not rely on them because their agencies treat every situation as unique. Two agencies indicated that smaller jurisdictions often do not have volumes high enough to meet nationally set thresholds, so general design guidance and considerations can be more useful than thresholds.

Six agencies use or are actively considering using thresholds in some instances.

• One agency uses thresholds from the MassDOT Separated Bike Lane Planning and Design Guide to determine whether to provide protected left and right turns.

• One agency is using turning-vehicle volume of 150 vehicles per hour as a threshold for providing an offset crossing but is considering if it should be adjusted.
• One agency is considering using a threshold for phase separation based on vehicle right-turn volume. For example, if turning volume is between 150-250 vehicles per hour, the agency will consider whether the bikeway could be realigned to the right of the right-turn lane without providing a signal. In these situations, agency staff also consider motor vehicle speed and intersection geometry before selecting a treatment.
• One agency is considering using a right-turn volume threshold of 100-200 vehicles per hour.
• One agency indicated that at intersections with over 150 turning vehicles, agency staff will review intersection geometry and assess whether to use signalization or some other design treatment (e.g., mixing zone or offset crossing).
• One agency is examining thresholds for bicycle and motor vehicle volumes and motor vehicle approach angles to dictate the design (e.g., length, width, and color) of pavement markings used to delineate conflict zones to ensure the pavement markings are easily visible to all roadway users.

One agency staff member noted that his agency does not use thresholds, beyond the MUTCD signal warrants, but if an intersection is in a school zone or high-crash intersection, the intersection will automatically be designed with a more protected bikeway treatment than might have otherwise been installed.

Design Issues and Constraints

Commonly mentioned design issues and constraints across most interviews included limited right-of-way, transit, cost (most often mentioned in reference to bike signals), heavy vehicle turning movements, and public response or political pushback (see Table 9). With the exception of cost and constrained right-of-way, most interviewees’ design issues and constraints can be categorized as issues associated with competing interests, particularly between freight, emergency vehicles, motorists, and bicyclists. In some cases, there were also noted conflicts between utility and stormwater management or green infrastructure and bicyclists.

Although interviewees from five agencies named motor vehicle delay and congestion as a constraint, nearly all mentioned that they consider it, but try to prioritize bicyclist safety over motor vehicle delay whenever possible. Two agencies also discussed a concern about diverting traffic from main streets onto secondary streets where there may be high pedestrian activity. Two agencies noted that in situations where there is not enough funding to provide complete separation between drivers and bicyclists along the entire bikeway, they try to focus on the conflict points (e.g., approaches to intersections and intersections) and provide a greater level of separation at these locations. Two agencies also mentioned that they would like to use more bike signals but the current requirements under the MUTCD are too restrictive.

Table 9. Design issues and constraints

Note: Values in this table are based on responses from 16 agencies.

*Specific examples include protected permissive phasing, presence of bikeways on curbside of turn lanes, and two-way or contra-flow bikeways.

Preferred design Treatments

Interviewees were asked to discuss their preferred design treatments and the treatments they use when specifically trying to improve bicyclist safety. It is unclear from some interviewees’ responses whether they were listing all of the design treatments that they use or only their preferred treatments. Interviewees were not asked why they prefer certain treatments over others; reasons could include feasibility, cost, design constraints, or other factors. In addition, when asked about treatments used specifically to address bicyclist safety, several interviewees noted that they always design and select treatments with safety in mind. For all of these reasons, the responses to these questions were combined and presented together in Table 10.

In general, agency staff strive to provide the most separation possible between bicyclists and motor vehicles. When funding and space is available, these goals are typically achieved through the use of bike signals or protected intersections. Where complete physical separation or separate signal phasing is not possible, agency staff try to increase driver visibility of bicyclists, improve predictability of road user behavior, and slow motor vehicle speeds. Four treatments stand out as the most commonly used and preferred treatments, these include green pavement markings, treatments to reduce curb radii, protected intersections (and other offset crossing variations with physical protection), and bike signals.

Interviewees at two agencies noted that in areas with a constrained right-of-way, particularly those with right-turn lanes that cannot be removed, they will install designs that raise the bikeway up to the sidewalk level in advance of the intersection and bicyclists are directed to the pedestrian crossing. Interviewees noted

• Five agencies are interested in protected intersection designs for more constrained areas than are depicted in national guidance documents.

Agencies also noted an interest in learning more about the best practices and evidence for designs for mixing zones, specifically in terms of the ideal length of the conflict zone or shared lane.

Table 11. Agency-identified design treatments with knowledge gaps

Knowledge Gaps Associated with Treatment Selection

Interviewees identified a variety of topics and research questions that, if answered, would improve their treatment selection process. Although this research project is unable to address all of the knowledge gaps identified by agency staff, this input can help hone our research efforts going forward and provides information about future research needs. Table 12 lists the knowledge gaps and research questions identified by agency staff. Some of the identified knowledge gaps may be beyond the scope of this project.

Table 12. Agency-identified knowledge gaps and research questions

Safety Analysis

Interviewees were asked to report their experience analyzing motor vehicle-bicycle crashes at intersections in their jurisdiction and the actions they have taken to mitigate the crashes. Most respondents reported that crash data was used in their agencies for analysis, however, the frequency of use varied significantly. While four agencies reported using crash data extensively for evaluating the entire network, one agency reported using it only for larger projects, and another for conducting analysis on an annual basis. Two jurisdictions reported using crash data to develop a proactive systemic approach towards improving safety, while another agency noted that they were using crash data to develop CMFs. Many interviewees also commented on issues with crash data, including rarity, under-reporting of crashes, and the impression that crash data is biased in that bicyclists are assumed to be more often at fault than they are in reality. One interviewee reported that although they conduct a crash analysis, they do not put too much emphasis on it due to the low crash numbers. Two interviewees also remarked on the need to understand cyclists’ comfort in addition to safety.

Only some agencies reported using surrogate data to evaluate bicyclist safety at intersections. Of these, volume and speed seem to be the most commonly used measures. Three agencies reported using Strava data or heat maps when count data are not available. Only two agencies have used conflict or near miss data to evaluate safety, and one agency wants to install cameras to capture near misses. Another agency reported having access to near miss data in a map format, but they have not evaluated it yet. One agency reported using the level of traffic stress. User complaint data was used by three agencies to evaluate safety.

Summary of Findings

The planners and engineers from city, county, and state agencies provided useful insights into the ways that practitioners across the U.S. select bikeway treatments for intersections. Although some of these treatments are fairly new, agency staff are installing them where they can and are eager for more information to help them improve bicyclist safety and overall traffic flow. Safety is a strong priority for these agency staff, as evident by the high prevalence of Vision Zero policies and interest in providing the greatest degree of separation between motorists and bicyclists feasible within existing political and design constraints.

The following summarizes the main themes for each topic covered in the interviews:

• Most agency staff consider a variety of factors when determining which treatments to install. Out of the 21 factors mentioned, the most common were pedestrian volume, motor vehicle speed, turning vehicle volume, and motor vehicle and bicycle volumes.
• Five of the 16 agencies interviewed use or are actively considering using thresholds for the factors they consider when selecting design treatments. Four of the five thresholds mentioned relate to turning vehicle volume, and one relates to bicycle and motor vehicle volumes and the angle of approach. Although speed was an important factor for many agencies, none of the interviewees mentioned thresholds for intersections related to speed. Three agencies expressed the need for thresholds for treatments beyond those which are available currently.
• The five design issues and constraints most commonly mentioned include constrained right-of-way, motor vehicle delay and congestion, transit, cost, and heavy vehicle turning volume. Nearly all interviewees mentioned that they consider motor vehicle delay but try to prioritize bicyclist safety over it whenever possible.
• The most commonly used intersection design treatments include green pavement markings, treatments to reduce curb radii, and protected intersections. These three treatments are used by nine, eight, and eight agencies, respectively.
• The most commonly identified research gaps relate to the use and regulations of bike signals and protected intersection designs (including constrained areas).

• Most agencies use crash data for analyses, however, the frequency of use varied significantly. Four agencies reported using crash data extensively for evaluating the entire network, one agency reported using it only for larger projects, and another for conducting analysis on an annual basis.