Smarter Intersections Start with Bicycle Detection

ACCESS THE BICYCLE DETECTION WHITE PAPER

Across the US, roughly two-thirds of reported bicycle crashes happen at intersections. Detecting the presence of people bicycling at or approaching signalized intersections and roadway crossings can offer traffic engineers additional tools and flexibility to improve the comfort and safety for this vulnerable group.

The implementation of modern bikeway projects often require our traffic signals to partially or fully protect people bicycling and walking from motor vehicle traffic. Solutions are often customized to the particular location and involve increasing usage of technology to make the intersection smarter and move more users with less delay.

In many North American cities, expanding intersections is either impossible or undesirable. Traffic engineers are being asked to provide intersection solutions that process more users more efficiently while adapting and integrating new facility types like separated bike lanes and dedicated transit lanes. There is a substantial diversity of technologies, both old and new, that give the traffic engineering profession tools to make North American signalized intersections safer, more efficient, and adaptive to changing needs and prevailing conditions. Detecting the presence of bicyclists at signalized intersections can provide many benefits, including:

• Reduction of the need for bicyclists to mount the sidewalk or position in a travel lane to call a signal
• Improvement in signal compliance by people bicycling
• Ability to call exclusive phases, such as bicycle signals, only when actuated to minimize unnecessary delay to other users
• Ability to detect an approaching bicyclist in advance of the intersection and calling a special phase or extended phase timing prior to arrival to minimize bicyclist delay
• Ability to extend the minimum green and/or clearance intervals to allow a bicyclist to safely clear an intersection should the vehicular timing not be sufficient
• Activation of crossing devices such as bicycle specific signals, Hybrid Beacons and Rectangular Rapid Flashing Beacons
• Activation of special electronic warnings for motorists to indicate bicyclist presence (flashing beacons or blank-out signs)
• Facilitate the ability to collect real-time continuous counts of bicycle activity

Alta’s newest white paper provides a deeper discussion on the various technologies that are available and provides insight on their strengths, weaknesses and practical applications to aid in the creation of smarter intersections that work for all users.

This white paper is intended as a resource for transportation practitioners who are seeking more detailed information on the various types of signal detection families and the considerations that would impact the selection and configuration of these technologies to detect bicyclists. While guidance on this subject exists, it is fragmented and does not comprehensively provide a full understanding of the capabilities and limitations of each type of detection. This white paper builds upon existing literature on the subject and combines it with practical experience with the hope it will help guide successful intersection projects and expand the industry knowledge base.