Studies Raise More Concerns About E-Scooter Safety, on Eve of Seattle Rollout


Photo by Vince Jacob on Unsplash

Last May, I wrote an article discussing the safety of e-scooters. At the time, Seattle was beginning to discuss a scooter-share program modeled after its existing bike-share program. Other cities aggressively rolled out their scooter share programs. But were they safe? My conclusion was that there simply was not enough data to draw a definitive answer on e-scooter safety, though the early results presented reasons to be concerned.

Now, as Seattle is well on its way to rolling out scooter-share later this spring, a new report on scooter injuries nationwide in 2018 brings us a bigger data set — and fresh reasons to be concerned.

The report, just published in the highly respected Journal of the American Medical Association (JAMA), pulls data from the National Electronic Injury Surveillance System (NEISS), which “provides national estimates of injuries that present to emergency departments across the United States.” The research team queried for injuries related to e-scooters from 2014-2018, then crunched the numbers.

They found a dramatic increase in e-scooter-related injuries over those five years: from 4,582 in 2014 to 8,016 in 2017, with a big jump up to 14,651 in 2018.  That alone is not entirely surprising given the rollout of scooter-share programs across the country. The raw numbers alone don’t tell us much about the safety of e-scooters. We need to put those numbers in the context of the overall amount of scooter-miles driven, and compare them to other modes of transportation.

According to a NACTO study, in 2018 there were 38.5 million e-scooter trips taken, with an average trip length of 1.2 miles. That gives us a total of 46.2 million scooter-miles driven — a much larger sample size than the few published studies of scooter-share pilots that we previously had to work with. With the 14,651 injuries recorded in the NEISS database, e-scooters have a rate of 3.17 injuries per 10,000 miles driven.  That’s somewhat higher than the figures reported from previous studies in Austin, TX and Portland, OR, which were about 2.2 injuries per 10,000 miles.

Let’s compare that to motor vehicles. According to the NHTSA, in 2018 there were 3.24 trillion miles driven in motor vehicles, with 2,710,000 injuries. That equates to .008 injuries per 10,000 miles — almost 400 times lower than the reported injury rate for scooters.

We can also look at the severity of the injuries, starting with the most severe: fatalities. There were 36,560 motor vehicle fatalities reported in 2018, a rate of 1.13 per 100 million miles. That translates to .522 fatalities per 46.2 million miles (the number of scooter-miles driven in 2018). In other words, if you took a random sample of 46.2 million miles of the 3.24 trillion driven in motor vehicles in 2018, there is a 50-50 chance that a single fatality would have occurred.

There is no directly comparable fatality report for e-scooters. The NEISS data set lists one fatality in 2018 (a man drove his scooter into a tree), but news reports suggest that there were more that year, and there are additional reports for 2019 as well. But even the scant reports are enough to conclude that the fatality rate for e-scooters (2+ in 46.2 million miles) is at least as high as for motor vehicles, and possibly higher.

The details of the e-scooter injury reports explain why: 32% of the scooter injuries were to the head. Studies have shown that a very low percentage of e-scooter riders wear helmets, even if they are required by law.

So the picture is now becoming very clear: e-scooters are as dangerous as motor vehicles, if not significantly more dangerous, and are far less regulated.

Last month the Seattle Department of Transportation (SDOT) published an initial SEPA analysis of its proposed scooter-share program, which gives us a preview of what we might see on Seattle streets in the coming months. In the report, it said that the city plans to issue permits for up to 20,000 scooters. That’s a high bar; bike-share has never reached nearly that level of deployment, though scooters have an advantage, being cheaper to buy and maintain. (These are some of the reasons that Jump and Lime are pushing to move from bikes to scooters quickly.)

So let’s pare that back and conservatively assume, at least for the first few years, 10,000 is a more reasonable expectation for the number of scooters deployed in Seattle. In Portland’s 2018 pilot, it saw an average of 2.9 trips per day, per scooter. At an average trip length of 1.2 miles, that would be 12.7 million scooter-miles in Seattle annually. At that level, we can expect about 4,000 scooter injuries per year — 11 per day. That would include 1,280 head injuries, and at least one predicted scooter-related fatality. If the scooter-share companies deploy more than 10,000 scooters (and the trips-per-bike ratio stays the same), then the injury statistics could be much higher.

This presents some very difficult policy questions for city officials. The SEPA report says that SDOT will ask the City Council to allow scooters in roadways, bike lanes, and multimodal trails, but not on sidewalks. But the city is under-invested in bike lanes currently, and Portland’s scooter-share study showed that scooter riders move to the sidewalk when they don’t feel safe riding on the street because of the speed of motor vehicles or the absence of a bike lane.  In addition, the low rate of riders wearing helmets, and the high rate of intoxication of scooter riders in collisions, suggests that altogether it would take an enormous enforcement effort by the city to make scooter-share safer in Seattle than what other cities have experienced.

San Diego is a case in point: it has chosen to ban scooters along its waterfront boardwalks because of the safety issues . In response to this and other efforts by the city to regulate scooters, just this week Lime decided to pull out of San Diego entirely.

SDOT’s SEPA report dismisses the injury and enforcement issues, claiming “The Scooter Share Pilot (SSP} is not anticipated to create a significant increase in the need for fire, police, or health care services.” Largely it bases this prediction upon its own experience with bike-share, and with a tortured reading of the results of the Portland scooter-share pilot. SDOT doesn’t even bother to estimate the number of collisions and injuries likely to result from a scooter-share program at the size it plans to permit, let alone the impact on first-responders, healthcare facilities, and traffic enforcement personnel. The SEPA “Determination of Non-significance” has been appealed to the Hearing Examiner, by former WSDOT Director Doug MacDonald.

There is currently no reason to believe that Seattle’s experience with scooter-share will be any improvement over San Diego, Portland, Austin, or the other U.S. cities that have rolled out scooter-share and seen an epidemic of injuries. And yet SDOT is planning to launch its program this spring, with the encouragement of some City Council members. What can possibly go wrong?

Kevin Schofield
Kevin Schofield
Kevin is a city hall reporter and the founder of SCC Insight, a web site focused on providing independent news and analysis of the Seattle City Council and Seattle City Hall in general. In a previous life, he worked for 26 years in the tech industry in a variety of positions but most notably as the COO of the research division at Microsoft. Kevin volunteers at the Woodland Park Zoo, where he is also on the Board of Directors. He is also the Vice Chair of the Board of Trustees of Harvey Mudd College.


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