AVs, Intersections and Acting for Safety

Last week I attended the Mobility21 Deployment Partner Consortium Symposium at Carnegie Mellon University. This annual symposium is an opportunity for researchers, industry leaders, and others to see what is happening at Carnegie Mellon’s University Transportation Center – one of five national centers funded by the United States Department of Transportation (US DOT).

This year’s keynote speaker was Carl Andersen, technical director of operations research and development for the Federal Highway Administration’s Turner-Fairbank Highway Research Center. He highlighted several research initiatives throughout his presentation including one on vulnerable road user detection at intersections using sensors, algorithms, and other technologies initially developed for automated vehicles. With this approach, researchers at Turner-Fairbank have been able to detect people at intersections at night and during snow events using sensors that go beyond the visual spectrum. 

By developing and helping deploy these technologies, traffic signals and crossings can be improved for people biking and walking without relying on push-buttons. There’s even the potential that the detection technology could notify drivers of people biking and walking where traffic signals do not exist or to supplement traffic signals.

Mr. Andersen’s highlighting of vulnerable road user detection at intersections also called attention to a recent Request for Information (RFI) by the US Department of Transportation, which expressed interest in “adapting existing and emerging automation technologies to accelerate the development of real-time roadway intersection safety and warning systems for both drivers and [vulnerable road users] in a cost-effective manner.”

Comments on the Request for Information can be submitted until November 15, 2022, and the League has already submitted our comments.

Our comments support enhancing the safety of vulnerable road users at intersections and acknowledge that the technologies contemplated by the RFI can improve safety, but we caution that technology is no replacement for safer intersection designs and reducing speeds so people are less likely to be killed or seriously injured if a crash occurs. Our experience working with leading automated vehicle developers shows us that AV technology works best when it is paired with safer infrastructure designs and slower speeds.

The most promising applications of enhanced detection of vulnerable road users at intersections would also require advanced driver assistance systems in new vehicles or tests for their effectiveness – something not currently required in the U.S. If an intersection can detect a person crossing in a snowstorm, that information is more valuable if the vehicle can receive it and act upon it by automatically braking if a crash is likely to occur. Unfortunately, neither the communication technology nor the automatic braking technology to enable said safety benefit are required in new vehicles.

The League is also concerned about new technology creating new demands on people biking and walking. Many researchers, including some concepts highlighted by Mr. Andersen, contemplate people biking and walking using cellphones to receive alerts or interact with smarter intersections. Some concepts include bike handlebar rumbles to warn of conflicts. These concepts demand people biking and walking have cellphones or other devices for the efficacy of systems and place novel burdens on people biking and walking that might be distracting and dangerous. Fortunately, the RFI states “the use of smart electronic devices by VRUs should not be a requirement for the efficacy of an intersection safety system.”

The League believes the priority for improving safety at intersections should start with improving roadway design at dangerous intersections by providing clear space for people biking and walking and reducing speeds so crashes are survivable. Technology enhancements may supplement that priority, but we do not believe technology alone will solve our traffic safety problems. We should not allow the potential – and speculative – safety benefits of new technology to obscure the task of implementing safer infrastructure designs today.