It's impressive that e-scooters have amassed between 40 to 60 million trips for a form of transportation that barely existed a year ago. But how many of those are displaced driving trips?
We don't really know. An often-cited, though unscientific, surveyin Portland found the car trip replacement level was pretty high — more than a third for locals and even higher (51 percent!) for tourists.
The survey's limited response rate makes it digestible only with more than a few grains of salt, but it wouldn't be surprising if e-scooters were replacing car trips at close to that range. Of course, even with healthy car-replacement levels, a large number of trips will replace walking, biking or transit as well. In those cases, they may actually increase the environmental impacts of some short trips, especially since e-scooters have such a short shelf life.
Scooter companies say safety will improve as scooter use becomes more widespread, creating pressure on city officials to redesign streets and add bike lanes.
Perhaps, as Bird asserts, e-scooters will eventually displace enough car trips to have a measurable impact on traffic safety.
Researchers Peter and Joel Jacobsen — whose research helped establish the "safety in numbers" effect for biking — saythey expect scooter injuries to decline as they become more common, as both drivers will become more aware of them and they help produce changes in the environment. The Jacobsens said, while there wasn't very much data, they would expect the safety outcomes of e-scooters to be similar to biking and walking.
Our very rough fatalities analysis supports that idea. But if the injuries show something different, it will be interesting to see how that impacts the industry and the regulatory environment. It's also possible it will help alleviate worries and lead to wider adoption.