Bicycle detection allows bicyclists to call a green signal at an intersection. Properly designed detection can help deter red light running and unsafe behaviors by reducing delay at signalized intersections. Technologies for detecting bicycles include inductive loops, microwave, video, magnetometers, and push buttons. Any technology should accurately detect bicyclists and provide clear guidance to the bicyclist on how to actuate detection (e.g., where to position his or her bicycle). The MUTCD provides guidance on stencil markings and signage related to signal detection.
Inductive loop vehicle detection at many signalized intersections is calibrated to the size or metallic mass of a vehicle. To accurately detect bicycles, the loop must be adjusted for bicycle metallic mass. If push buttons are provided, they should be located so bicyclists can activate the signal without dismounting. Thus, bicycle push buttons may be unsuitable as primary detectors on roadways, but may be best used on shared use paths or trails.
Signalized intersections should include detection for bicyclists to facilitate safe, comfortable, and convenient crossings at intersections for bicyclists while also minimizing delay.
- Detection shall be placed where bicycles are intended to travel and/or wait.
- If leading signal detection is provided, it should be located along a bike lane or in the outside travel lane.
- Video detection systems may have problems detecting bicycles, especially during poor lighting and weather conditions.
- If a pushbutton is used, the location of the device should not require bicyclists to dismount or be rerouted out of the way or onto the sidewalk to activate the phase. Signage should supplement the signal to alert bicyclists of the required activation to prompt the green phase.
Bicycle detection devices are used to determine if a bicyclist is waiting for the signal. Costs vary depending on the type of technology used, but bicycle loop detectors embedded in the pavement are $1,920 on average, and can range from $1,070 to $2,680. More detailed cost information is provided here.