United States Bicycle Signal Resources

This section is intended to summarize available guidance to support the planning, design, and implementation of bicycle signals. Guidance documents listed below include those within the United States and are listed in table format so practitioners can identify a specific area of interest and navigate to the appropriate guidance document quickly.

Practitioners within the United States are always advised to consider state and local standards, as well as the 2009 Manual on Uniform Traffic Control Devices (MUTCD) and Interim Approval for the Optional Use of Bicycle Signal Faces (IA-16), which contain national design, application, placement standards, guidance, options, and support provisions for traffic control devices used with bicycle facilities. The jurisdiction implementing the bicycle signal must ensure that the project complies with the MUTCD and IA-16 and must request specific approval from the Federal Highway Administration (FHWA) using the procedure outlined in Paragraphs 14 through 22 of Section 1A.10 of the MUTCD, unless the jurisdiction has prior approval for the subject traffic control device. The list of state and local highway agencies that have been granted an Interim Approval are shown in the following document: https://mutcd.fhwa.dot.gov/resources/interim_approval/ialistreq.htm#ia16.

The 2009 MUTCD does not specifically address the use of bicycle symbols within traffic signal faces.  However, design and operation of bicycle signal heads should consider general MUTCD guidance on standards for traffic signals where applicable, including positions of signal indications, visibility, aiming, and shielding of signal faces. Engineering judgment should be used to ensure that the design of bicycle signal heads is optimal for each installation. General design guidance is provided for bicycle signage and pavement markings for bicyclists to actuate the traffic signal in Section 9B.13 and Section 9C.05, respectively. This is not necessarily specific for situations where bicycle signal faces exist at an intersection. Section 9D.01 and Section 9D.02 discuss warrants and traffic signal operations when considering the optional use of signal faces to control bicycle movements, respectively. Part 9 of the MUTCD can be viewed at the following link: https://mutcd.fhwa.dot.gov/pdfs/2009r1r2/part9.pdf#page=28.

FHWA Interim Approval for the Optional Use of Bicycle Signal Faces (IA-16)

A major reason for the lack of bicycle signal use prior to 2013 was that Part 9 Traffic Control for Bicycle Facilities of MUTCD included provisions for circular signal indications to control bicycle traffic but did not explicitly define the use of bicycle symbols within the signal faces. Some transportation professionals postulated that use of bicycle signal faces in the United States was only allowed on an experimental basis through the MUTCD Request to Experiment (RTE) process, which required documentation and evaluation of bicycle signal applications. On December 24, 2013, FHWA issued IA-16, which gave city, county, and state agencies the option to implement signal faces with bicycle signals under certain requirements.

The IA-16 allows interim use pending incorporation in an official rulemaking to update the MUTCD. The interim approval does not require the use of bicycle signals but outlines a list of standards and guidance if they are to be considered. Bicycle symbols within signal faces are not provided for in the MUTCD, so the new provision of bicycle symbols within signal faces is a key component of the interim approval. As stated above, unless they already have requested and received approval for the use of bicycle signal faces, agencies must request permission from FHWA to use bicycle signal faces and are expected to agree to the terms and conditions outlined in IA-16, which can be access at the following link: https://mutcd.fhwa.dot.gov/resources/interim_approval/ia16/ia16.pdf

On December 11, 2020, FHWA issued a Notice of Proposed Amendments (NPA) which included several wide-ranging revisions to the MUTCD. This NPA, which represents the first comprehensive update to the MUTCD in more than 10 years, includes a new chapter for bicycle signals that outlines provisions for the application, design, and operation of bicycle signals. The public comment period for the NPA closed on May 14, 2021. Based on their evaluations of comments received, FHWA may subsequently issue a final rule concerning the changes that will be made to the MUTCD. Based on the content included in the NPA, expanded design guidance for bicycle signals is anticipated with this MUTCD update. Meanwhile, IA-16 represents the most current design guidance for bicycle signals.

Bicycle signals, when appropriately located and designed, make traveling through intersections safer for bicyclists. Bicycle signals are typically used to minimize conflicts between bicyclists and other vehicles and to clarify when a bicyclist should enter an intersection. Additionally, the expanded use of bikeway design applications, such as buffered and separated bike lanes, two-way bikeways, and protected intersections has resulted in a desire by many jurisdictions to provide bicycle signals, as these signals can provide bicyclists more positive guidance through intersections that include these facility types. Bicycle signals are often a key component of the overall bicycle infrastructure network and are beneficial in enhancing wayfinding and minimizing conflicts due to complex traffic signal phasing at intersections.

The limitations in the application of bicycle signals contained in IA-16 has resulted in many agencies using engineering judgment to address specific site conditions that are either not addressed or not addressed in adequate detail in the design guidance presented in IA-16. Also, there are other factors to consider when designing or operating bicycle signals. These include detection of bicycles, phasing and timing of bicycle signals, signal head sizing and positioning, backplate color, and pavement markings and signs for bicycles. This resource hub will serve as a valuable source for information on how to address these types of issues.

Figure 2. Typical Arrangements of Signal Sections in Bicycle Signal Faces Long Description. Source: FHWA MUTCD Attachment IA-16-1.

FHWA Official Interpretation February 12, 2014, #9(09)-47 (I) on Clarification of IA-16

In February 2014, FHWA issued a clarification memo (see link below) which provides additional information clarifying the requirements of IA-16. The primary role of the interpretation was to clarify questions related to protection for cyclists that are facing a green or yellow bicycle signal face. To follow IA-16, bicycles moving on a green or yellow bicycle signal face cannot be in conflict with any simultaneous vehicle movement, including turns on red. Clarifications of what constitutes a conflict, and how practitioners can comply with this requirement are provided in the interpretation: https://mutcd.fhwa.dot.gov/resources/interpretations/pdf/9_09_47.pdf

Design Guidance Summary

The following table identifies how current design guidance documents address key areas related to bicycle signal design.  For additional reference, Canadian and international design guidance documents are included in the table.  The list of guidance topics is not intended to be exhaustive but does document the most common challenges and design components practitioners have expressed through ITE committee discussions.  As the state of the practice evolves, the list may be updated.  The resources are listed from nationally-adopted guidance documents (left) to jurisdiction specific guidance documents (right).

Table 1. Design Guidance Table

FHWA Separated Bike Lane Planning & Design Guide (2015)

The FHWA Separated Bike Lane Planning & Design Guide outlines a variety of design treatments for exclusive bike facilities separated from adjacent motor vehicle traffic along a roadway. This guide contains detailed intersection design information including turning movement operations, intersection markings, signalization strategies, and traffic signal phasing. Chapter 5, Menu of Design Recommendations, contains details for separating bicycle through movements from conflicting motor vehicle movements using bicycle signals and considers other alternatives to bicycle signals.

Advantages

• Considerations for bike-friendly traffic signal phasing is provided to encourage a flexible design approach for accommodating bicycle signals at signalized intersections for both one-way and two-way separated facilities. General recommendations for traffic signal phasing and coordination are provided based on bicycle progression speed.
• Additional design alternatives are discussed in lieu of providing bicycle signals in order to increase bicyclist comfort and reduce intersection movement conflicts. Alternative design treatments include the bend-in/bend-out design, lateral shift, and mixing zones.

Disadvantages

• Specific design details of bicycle signals are limited. General consideration is given to visibility requirements, turn restrictions, and geometric conditions.

The FHWA Separated Bike Lane Planning & Design Guide, Chapter 5 – Menu of Design Recommendations can be found at the following link: https://www.fhwa.dot.gov/environment/bicycle_pedestrian/publications/separated_bikelane_pdg/separatedbikelane_pdg.pdf#page=115

A webpage summary of the FHWA Separated Bike Lane Planning & Design Guide, Chapter 5 – Menu of Design Recommendations can be found at the following link: https://www.fhwa.dot.gov/environment/bicycle_pedestrian/publications/separated_bikelane_pdg/page10.cfm

AASHTO Guide for the Development of Bicycle Facilities, 4^th Edition (2012)

This guide provides information on how to accommodate bicycle travel and operations in most riding environments including bike lanes on one-way and two-way streets and shared-use paths. It does not include information regarding the use of bicycle signal faces. An update to the 4^th Edition is anticipated soon.

Section 4.12.4 of the AASHTO Guide for the Development of Bicycle Facilities addresses the operating characteristics of bicycles at signalized intersections and provides guidance for adjusting signal operations for bicyclists where appropriate. Specific traffic signal parameters that are discussed for bicyclists’ needs include the minimum green interval, all-red interval, and extension time.

Advantages

• Specific calculations for adjusting the bicycle minimum green time are discussed in detail for stopped bicyclists at an intersection and the adequacy of any red clearance interval and any extension time, if provided, for consideration of rolling bicyclists at an intersection.
• Various technologies for bicycle detection at signalized intersections are discussed in detail, including inductive loops, microwave, video, magnetometers, and push buttons.

Disadvantages

• Specific items pertaining to the design of bicycle signal faces are not addressed in this document as IA-16 had not been developed at the time of this publication. There was no large interest in using bicycle signals when the guide’s 4^th edition was prepared, so there is no consideration of bicycle signals in the guide.  A new edition is being prepared and more information on bicycle signals is expected to be included when this edition is completed and distributed.

The AASHTO Guide for the Development of Bicycle Facilities, 4^th Edition can be found at the following link: https://njdotlocalaidrc.com/perch/resources/aashto-gbf-4-2012-bicycle.pdf#page=105

NACTO Urban Bikeway Design Guide (2014)

This design guide includes specific design treatments used for bicycle facilities in the urban context around the world and in many cities around the United States. Many of the treatments in this guide are considered innovative as they had not been previously adopted in other design guides at that time.

Benefits and typical applications for the optional use of bicycle signal heads are discussed in detail. Detailed graphics outline the required, recommended, and optional features when practitioners are designing bicycle signals at intersection locations.

Advantages

• Case studies from various U.S. cities and technical references provide practitioners various contextual applications for bicycle signals as well as detailed guidance and technical references for signal detection and actuation.
• The guide presents a wide array of design treatments that can be applied in order to mitigate intersection conflicts if bicycle signal heads are not being considered or not feasible.

Disadvantages

• Because of potential conflicts with the MUTCD, some jurisdictions may choose to not implement the guidelines set forth in this document, particularly for the consideration of bicycle signals.

The NACTO Urban Bikeway Design Guide can be found at the following link: https://nacto.org/publication/urban-bikeway-design-guide/bicycle-signals/bicycle-signal-heads/

MassDOT Separated Bike Lane Planning & Design Guide, Chapter 6, Signals (2015)

This state guidance is among the most detailed and comprehensive of state planning and design publications available regarding the use of bicycle signals, so it is included as a guidance document of national significance. It may be a useful resource for other agencies developing guidelines. The Massachusetts Department of Transportation (MassDOT) publication provides specific guidance on the planning, design, and operations for separated bike lanes. Chapter 6 is dedicated to the design and operations of bicycle signals. This chapter has information specific to signal design, equipment selection guidance, and refers to the FHWA IA-16 and the 2009 MUTCD. Placement, size, and visibility of signal heads as well as phasing and timing considerations are all included in this guide. Detailed graphics and tables outlining movement conflicts and design tradeoffs make the MassDOT Separated Bike Lane Planning & Design Guide a useful resource for design practitioners, even for those working outside of Mass DOT jurisdiction.

Advantages

• Considerations for time-separated bicycle movements at signalized intersections are presented for separated bike lane operations in order to eliminate conflicts based on hourly motor vehicle turning volumes. Scenarios where provision of separate signal phases should be considered are also presented.
• The guide references various MUTCD requirements for the application of traffic signals and specifically notes the variation allowed for the design of bicycle signals as permitted by IA-16. Such design elements include visibility, lateral positioning, longitudinal positioning, and mounting height of the signal face.
• Extensive guidance regarding primary scenarios for restricting right turns on red for motor vehicle traffic turning across a separated bike lane is discussed at length. This is an important design detail for practitioners to consider in order to eliminate potential motor vehicle turning conflicts at signalized intersections.

Disadvantages

• Because of potential conflicts with the MUTCD, some jurisdictions may choose to not implement the guidelines set forth in this document, particularly for the consideration of bicycle signals and time-separated bicycle phasing scenarios. Various jurisdictions may emphasize different tradeoffs when considering separated bike lane traffic signal operations.
• State laws may differ from the Commonwealth of Massachusetts.

The MassDOT Separated Bike Lane Planning & Design Guide, Chapter 6 Signals can be found at the following link: https://www.mass.gov/doc/chapter-6-signals/download

State Pedestrian/Bicycle Coordinators

A list of pedestrian/bicycle coordinators for each of the states can be found at the following link: https://www.fhwa.dot.gov/environment/bicycle_pedestrian/state_contacts.cfm