Injury rates for e-bikes are four times higher, while injury rates for e-scooters are almost double

Micromobility generally refers to small, slow, human-powered or electric transportation. Reports suggest that between 2019 and 2022, sales of electric bikes will grow by 269%, surpassing sales of electric cars and trucks.

“Our findings highlight the urgent need to improve micromobility injury surveillance and identify strategies for cities to improve user safety so that micromobility is a safe, sustainable, equitable and healthy mode of transportation,” said first author Katherine Burford, PhD, of Columbia Mailman School's Department of Epidemiology. “Understanding how injury types and risk factors vary by mode can inform emergency department utilization, resource allocation, and intervention strategies and policies to promote safe micromobility use.”

Researchers used 2019-2022 data from the National Electronic Injury Surveillance System (NEISS) to describe the national burden of injuries associated with micromobility devices and compare patterns and trends among an estimated 1,933,296 injuries associated with e-bikes, bicycles, hoverboards, and e-scooters. NEISS surveys a sample of 96 U.S. hospitals with at least six beds and an emergency department (ED).

Of the total 48,857,022 injuries seen in emergency departments between 2019 and 2022, an estimated 1,933,296 were micromobility-related injuries. Of these, bicycle-related injuries were the most common, accounting for 33.2 per 1,000 emergency department injuries. There were 3.4 injuries from e-scooters, 1.2 injuries from e-bikes seen in emergency departments, and 1.8 injuries from hoverboards.

Of the estimated injuries from hoverboards, 76% were people under the age of 18, compared with 14.5% from e-bikes and 16% from e-scooters.

In contrast, 57% of injuries on electric scooters and 49% of injuries on electric bicycles.

Bicycle injuries are concentrated among people ages 18 to 44. Older adults (ages 65 to 84) have the highest rate of micromobility-related injuries, followed by bicycle-related injuries and then e-bike-related injuries.

A higher proportion of men were injured in e-scooter and bicycle-related accidents than women.

Among e-scooter injuries, alcohol use was the most common cause, followed by e-bike injuries. In cases where helmet use was reported, injured bicycle and e-bike users were more likely to use helmets than e-scooter and hoverboard users in approximately 20 percent of cases. Hoverboard injuries had the lowest rates of helmet use, and these injuries were also more likely to be diagnosed as a concussion.

Overall, hoverboard-related injury rates declined over the four-year period, even in the pediatric population, which may partially explain the American Academy of Pediatrics' 2018 warning of the dangers of hoverboard use. “Conversely, the large increase in motorized micromobility injuries we are experiencing could be due to a lack of access to, education, and regulation of protective equipment, as shared micromobility systems, such as New York City's Citi Bike program, are not required to provide helmets to users,” said Andrew Rundle, PhD, professor of epidemiology and senior author.

In a previous paper on alcohol and bicycle crashes, the authors noted that complete and accurate data on helmet use, drug use, other risk factors, and coding of micromobility devices remain major limitations in national public-use datasets such as NEISS.

“There is a lack of laws regarding where micromobility devices can be ridden, and laws regulating the riding of these devices under the influence of alcohol or other recreational drugs are inconsistent and have historically been difficult to pass,” Burford said.

Burford and Rundle also note that increasing the availability of active transportation infrastructure, such as bike lanes, near high-use areas like downtowns may offer cities an alternative, more quickly implemented strategy for making roads safer for micromobility riders. For example, to support urban designs that allow safe micromobility in congested downtown areas, Burford and his colleagues plan research to identify features of the built environment that reduce the risk of injury for micromobility riders.

Co-authors are Nicole Itzkowitz of the Columbia University Mailman School of Public Health, Charles Di Maggio of the New York University Grossman School of Medicine, and Stephen Mooney of the University of Washington School of Public Health.

This research was supported by grants T32ES007322-21 and 5T32ES007322-22 from the National Institute of Environmental Health Sciences, and grant R49CE003094 from the Centers for Disease Control and Prevention.

The authors have no conflicts of interest to disclose.