Low caps on e-scooter speeds encourage sidewalk riding

(May 22, 2023) Many cities are turning to speed limiters for electric scooters to address concerns about rider safety and conflicts with pedestrians. But mandating low travel speeds may mean more e-scooters on the sidewalks, a new study from the Insurance Institute for Highway Safety suggests.

“Our results show that restricting scooters to low speeds offers a trade-off,” said Jessica Cicchino, IIHS vice president of research and the study’s lead author. “At slow speeds, riders are more likely to choose the sidewalk over the road. That puts them in less danger from cars but could mean more conflicts with people on foot.”

The first shared e-scooter program was launched in the United States in 2017. But as ridership has bloomed, so have injuries and citizen complaints. In response, many towns and cities have required speed limiters for shared e-scooters. A 15 mph maximum is common. Some companies also restrict their e-scooters to that speed even where it is not required by law.

To help understand the effect of different maximum speeds, IIHS researchers compared rider behavior in Austin, Texas, and Washington, D.C. Austin caps shared e-scooter speeds at 20 mph. In D.C., the maximum is 10 mph — one of the lowest in the United States. Neither city has an effective way to require speed limiters on privately owned scooters.

In both cities, e-scooter riders overwhelmingly rode in bike lanes where they were available. Where there were no bike lanes, however, D.C. riders were 44 percent more likely than Austin riders to choose to ride on the sidewalk.

D.C. riders were more likely to favor the sidewalk even though vehicle traffic was heavier at the 16 Austin observation sites. There also were many more pedestrians and cyclists at the 16 D.C. sites. Overall, however, riders tended to choose the sidewalk when motor vehicle traffic was heavier, as well as on arterials and two-way roads. In contrast, the researchers saw an increase in e-scooter riders in vehicle travel lanes on weekends, possibly because of lighter traffic.

E-scooter riders are doubtless safer from fatal injuries when they’re not sharing the road with motor vehicles. However, the net impact of sidewalk riding on less serious injuries to e-scooter users and pedestrians is unclear. A previous IIHS study showed that most e-scooter rider injuries in D.C. happened on the sidewalk but also that injuries that occurred on the road were more severe.

“E-scooter users clearly take risk into account when choosing where to ride,” said Cicchino. “Many are also conscious of the risk of hitting a pedestrian. E-scooter speeds were lower on sidewalks than on roads or bike lanes in both Austin and D.C.”

The highest sidewalk travel speeds differed between the two cities, however. In D.C., less than 1 in 5 e-scooter users rode at a speed of 10 mph or higher on the sidewalk, compared with 2 in 5 in Austin. A substantial portion of Austin riders sped along at 15 mph or more on the sidewalk as well.

"Slowing down the fastest sidewalk riders should help prevent crashes and reduce the severity of injuries when e-scooters hit pedestrians,” Cicchino said. “The clear preference for bike lanes also gives communities another reason to focus on expanding their bicycle networks.”

The researchers also analyzed rider behavior in D.C.’s central business district, where sidewalk riding is prohibited. Despite the ban, they found that two-thirds of e-scooter users rode on the sidewalks at locations without bike lanes. Riders in areas of D.C.’s central business district without bike lanes were also 38 percent more likely than Austin riders to choose the sidewalk over the street.

There’s little evidence sidewalk bans are any more effective elsewhere. Nevertheless, two-thirds of U.S. communities are considering them or have them in place already, according to a 2022 survey by the Behavioral Traffic Safety Cooperative Research Program. Others are mulling banning e-scooters from all or certain roads. A pilot program in Denver, for example, barred e-scooters from riding in vehicle travel lanes where the speed limit for motor vehicles was greater than 30 mph.

Improvements in e-scooter technology could offer an alternative solution. Some e-scooter companies are deploying systems that can detect when their e-scooters are on sidewalks, for example. As this technology matures, it could be used to apply separate speed restrictions for sidewalk riders or prevent sidewalk riding altogether in key locations.

In the future, that could make speed restrictions an unqualified win for safety, rather than a trade-off.