Safety Treatments for Unsignalized Bike Path Street Crossings
By Alejandro Angel, PhD, PE, PTOE
Bicycling has been steadily growing in popularity in the United States over the last 10 years. In fact, statistics show that the number of people commuting to work increased 60% between 2000 and 2010. Unfortunately, the number of bike fatalities has also increased, up 15% during the 10-year period from 2003 and 2012.
When you hear about a collision involving a motorist and a bicyclist, it often involves an urban street where bicyclists and drivers must share the road. But crashes and near misses are also a challenge where a two-way bike path (Class I bikeway) intersects a street at an unsignalized location.
Part of the problem is that upon reaching a stop or yield sign, many drivers are used to only looking to their left for conflicting traffic and may therefore miss a cyclist approaching from their right. On the other hand, bike paths controlled by stop signs are also problematic because this requires bicyclists to lose all their momentum and, in the case of serious cyclists, it requires them to unclip their shoes from the pedals. The result is low bicyclist compliance with the stop signs.
Compounding the problem is the fact that many of these intersections have poor sight visibility to the right because they were designed for vehicles to only check conflicts to their left. Many bike paths have also been added to existing corridors without consideration of the sight distance necessary to see vehicles approaching unsignalized intersections.
In most cases, agencies implement additional or special signing and striping treatments to try to mitigate the problem, but those solutions don’t get to the root of the problem. In addition to Education and Enforcement, effective solutions need to incorporate the following Engineering elements:
- Make bicyclists and drivers be aware of each other
- Reduce the speeds of all users at the conflict points
- Improve visibility, and
- Avoid measures that rely on treatments with documented low compliance (i.e. stop signs for cyclists)
Some agencies have considered physical barriers (such as speed bumps) on bike paths to control speeds, but in general those treatments could increase the risk of injury to cyclists and compromise accessibility for disabled users.
Some solutions we have recommended and implemented at Psomas include:
- Raised bike path crossings, or “Speed Tables,” which both require motorists to slow down and make bicyclists and pedestrians more visible
- Green striping to call attention to a bike crossing
- Improved angle of intersections, so bicyclists can better see approaching vehicles
- Removal of sight obstructions such as vegetation and decorative walls
- Detectors at intersections that alert drivers when a bike is crossing (with blank out LED signs)
- Bike circles (essentially a small roundabout for bikes) to slow down bicyclists approaching a roadway crossing
- Signalization of the crossing where required, such as hybrid beacons (HAWKs) specifically modified for bicyclists, TOUCAN signals, and Rectangular Rapid Flashing Beacons
While some of these solutions have proved effective at multiple locations, others (such as the bike circle) are just experimental at this point and could present their own set of issues. Still, the fact remains that unsignalized two-way bike path street crossings are challenging, and that effective, creative solutions must be found to make our communities safer for motorists and bicyclists alike.
Alejandro Angel, PhD, PE, PTOE is vice president and director of Arizona Transportation and Traffic Engineering at Psomas.