Bicycle Safety Guide and Countermeasure Selection System

 

Bicycle signal indication with bicycle stenciled lenses. Flickr - Oregon DOT


 

 

 

Bicycle Signal Heads

Bicycle signal heads are an additional traffic-control device installed at signalized intersections to provide guidance and right-of-way control in specific circumstances. Bicycle signal heads can be accomplished with standard lenses or lenses with bicycle symbols. The 2012 AASHTO Guide for the Development of Bicycle Facilities indicates that a standard three-lens signal head with a supplemental sign that says BICYCLE SIGNAL could be used at locations where bicycles share a signal phase with pedestrians or have their own phase. The FHWA has issued an interim approval for the optional use of bicycle signals heads with green, yellow, and red bicycle symbols.

A bicycle signal should be considered in the following scenarios:

  • At intersections with bicycle-specific movements such as a contraflow bike lane or separated bike lane, a bicycle signal may be necessary to indicate right-of-way to the bicyclist.
  • At intersections where bicycle movements need to be separated in time from a conflicting vehicular movement, such as locations with a high volume of left- or right-turns, bicycle signals can allow for a separate bicycle phase or movement.
  • One application that is currently under experimentation occurs at locations with high vehicle turning volumes, cyclists could benefit from a bicycle signal with a Leading Bicycle Interval (LBI), similar to a Leading Pedestrian Interval, an LBI gives bicyclists a head start at intersections by giving bicyclists several seconds of green time before the concurrent vehicular movement receives the green indication. This reduces the risk of conflicts between bicyclists and turning traffic and also provides bicyclists an opportunity to make a lane change or left turn.
  • At intersections with high bicycle volumes where bicyclists would otherwise follow the pedestrian indication, such as shared-use path crossings, a bicycle signal can reduce confusion.
  • Pedestrian signal timing is inappropriate for bicyclists who travel at higher speeds, so a bicycle signal would allow bicyclists to cross legally during most of the flashing don't walk interval.
  • At intersections where bicyclists would normally follow the vehicular indication, a bicycle signal provides a longer clearance interval more suitable to bicyclists' speeds so bicyclists do not get caught in the path of an oncoming vehicle.

Purpose

Bicycle signal heads may be used to improve safety and operations at signalized intersections where bicycles require specific guidance.

Considerations

  • Bicycle signal heads should be placed in a location that is clearly visible to approaching bicyclists.
  • The signal should be installed with actuation and appropriate detection for bicyclists.
  • Consider the movement of bicyclists when selecting minimum green times and clearance intervals due to slower speeds and start-up times. See the optimizing signal timing for bicyclists for additional details.
  • Intersection crossing markings should be considered where the bicycle travel path through the intersection is unusual.
  • Consider supplemental, near-side signals with smaller lenses and lower mounting height to provide additional visibility and clarity for bicyclists.
  • Visual variations between vehicular signal heads and bicycle-specific signal heads (e.g., size, louvers, backplate color) should be considered.

Careful consideration should be given to whether a bicycle signal is the most appropriate solution. The addition of a bicycle signal and a bicycle-only phase may increase delay for all users and may result in decreases in compliance. However, bicycle signals may also provide increased comfort, especially for less experienced bicyclists. As such, each intersection should be studied to balance the safety and operational needs of pedestrians, bicyclists, and motorists.

Estimated Cost

Bicycle signals can cost as little as $1,000 per signal face and increase with the number of signal heads and bicycle detection required.

References

To view references for this countermeasure group click here.

Case Studies

Davis, California