The City Electric sits down with Dr. Chris Cherry

The University of Tennessee’s Dr. Chris Cherry is a fixture in the micromobility world. He has published dozens of leading papers and seems to always find himself in the middle of the electric intersection of policy, engineering, and safety.

Dr. Chris Cherry, in situ

Just as he was gearing up for the release of a big safety study, Dr. Cherry sat down with The City Electric to share the study’s major findings and opine more broadly about why Vision Zero is still out of reach.

TCE: Let’s talk about your new study. What are the main findings? How do scooter crashes compare to bike crashes?

Cherry: We looked at scooter and bike crashes in the urban core of Nashville. Interestingly, we found via police data that there are fewer scooter crashes than bike crashes, even though, according to leading local bike policy groups, scooter riders outnumber bikers by 3 to 1 or more.

Intersections are important for both modes — that’s where crashes are happening. But most of the crashes we found for scooters happen from the sidewalk to the crosswalk and intersection, whereas most bike crashes are in the street. Maybe this is more a relative function of where they are operating, but with scooter riders we are finding a lot more wrong way riding — people ride whichever way they want to ride, often against traffic, and that can lead to conflict when scooter riders suddenly pop out onto the street. Intoxication was not a big factor in our study, somewhat counter to other studies. It was not really a factor for bikers or scooter riders. Another finding that is somewhat of a departure from some other studies: we found more daytime crashes vs night, even when we accounted for exposure. The implication here is that strict curfews for riders, particularly as vehicles have become more visible with better lighting and reflectors, may be misguided. Nighttime riding may even be safer, when fewer cars are on the road. We also found that car and truck speed, as you might expect, was a major factor, especially in the more serious crashes.

There has to be more intersection management, enforcement. Car drivers are not taking care. We found that most of the drivers who are hitting people on scooters are suburban or exurban drivers who are possibly not used to driving in the urban core. These drivers are not habituated to driving in a dense urban environment teeming with vulnerable road users. Scooter riders and bicyclists were close to home — two-thirds of the people riding scooters are not tourists, they are locals getting around their own neighborhoods — local people using scooters as basic transportation. The drivers are interlopers, they don’t seem to be aware of their surroundings and are unaccustomed to the risks associated with driving in a dense area.

TCE: That’s interesting. If only there was a way to automatically limit a driver’s speed… You were quoted yesterday in a story about speed being responsible for increasing traffic deaths in Washington, DC. You identify motor vehicle speeds as a factor that needs to be brought under control, and you make an analogy with the speed control that exists on shared e-scooters. Can you expound on that? Are you implying that what is good for scooters is good for cars?

Cherry: When it comes to safety, and achieving vision zero and checking motor vehicle speeds, I think we first have to acknowledge that the traditional engineering approach has failed. DC does have speed cameras, but they are not everywhere. Are they on neighborhood streets, where vulnerable road users are? Or are they only on highways and major arterials? This gets back to engineering, the passive approach to safety, the 85th percentile rule, and speed limits and street design determined by status quo driver behavior. Traffic engineers have to get beyond their timidity andhabit of coddling drivers. Yes, if speed control is good for scooters it’s great for cars and trucks because the consequences of driving at high speed are so much more severe due to the basic physics involved in driving heavier vehicles.

A lot of the engineers I talk to feel powerless, that they are bound to AASHTO or their political masters. Politics matter. If you don’t have a mayor or councilpersons who lead knowing that road deaths are preventable, then politics will prevent these common-sense changes enacted. Eventually we have to say if we care about safety we have to remake the road system accordingly.

Here, locally in Knoxville, we had a hazardous greenway detour because engineers were afraid of a potential landslide. So to avoid this remote possibility, they put the onus on bicyclists and scooter riders to take a detour onto a major unprotected arterial. So people are exposed to more risk but the agency is exposed to less liability. This is perverse. We have to turn that on its head and engineers must lead through excellent and safe design and management of the transportation system. I hope to teach a generation of future engineers that will do just that and conduct research that gives engineers the tools they need to make decisions based on evidence.

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