MTI Electric Bicycle Safety Study Identifies Illegal, Over-Powered Devices as Key Problem

The Mineta Transportation Institute (MTI) has released a report commissioned by the California Legislature: Exploring Electric Bicycle Safety Performance Data and Policy Options for California. The study offers recommendations for how California can support the twin goals of expanding electric bicycle use and protecting the safety of electric bicycle riders and other road users. 

Numerous media stories have reported skyrocketing crashes and injuries involving electric bicycles, but the study authors warn that these reports must be interpreted with caution. While each injury or death is a unique tragedy, policymakers also need to understand the relative scale of the safety problem in order to make evidence-based judgements about appropriate policy. The most recent state and national data available show that although electric bicycle incidents on average cause more serious injuries than conventional pedal bicycle injuries, incidents with electric bicycles are still comparatively rare. As lead study author Asha Weinstein Agrawal, PhD, explains, “California emergency room data from 2023 shows that for each electric bicycle injury, there were 9 times more people injured by pedal bicycles and 60 times more people injured in motor vehicle incidents.”

Another reason for caution in interpreting the number of crashes and injuries attributed to electric bicycles is that some unknown fraction of these were not caused by legal electric bicycles. California, like most states, limits the motor on electric bicycles to 750 watts of power and the top motor-assisted speed to either 20 or 28 mph, depending on how the rider activates the motor. However, many devices marketed in California as electric bicycles have much higher motor power and/or faster motor-assisted speed than the law allows. 

While nobody knows how many of these illegal electric bicycles are on the road, the percentage might be quite high. Counts of electric two-wheelers parked at a dozen northern California middle and high schools found that almost 90% may not meet the standards for legal electric bicycles. Some of these devices have as much as eight times more power than legal limits.

Study author Kevin Fang, PhD, observes that many Californians may be purchasing illegal devices without realizing it. “Marketing materials show overpowered devices being ridden on city streets. Only consumers who think to look at the fine print would realize that the device’s high motor power and top speeds make it illegal to ride on the street.” California could adopt strict disclosure requirements on retailers, so that buyers clearly understand whether or not the device they buy is a legal electric bicycle in California that can be ridden on streets and roads.

Another policy change the authors recommend is that the state revise the definition of electric bicycles to specify that the 750-watt maximum motor power refers to peak power, not continuous power. That change would bring California’s rules more closely in line with power maximums in the rest of the world.

Currently, California law does not specify whether the 750 watt maximum applies to peak power (the most power that a motor can ever generate, output that cannot be sustained over time) or continuous power (the power output a motor can sustain without overheating). If legal bicycles are allowed to have 750 watts of continuous power, then riders have at their command a motor which is the equivalent to one horsepower. (One horsepower is 750 watts.) By contrast, a motor with a 750-watt maximum peak power would give electric bicycle riders more or less the power of a professional bicyclist. 

The authors argue that specifying 750 watts as the maximum peak power would limit electric bicycles to a power level that is compatible with them being regulated like conventional bicycles, which California law generally does. “The fact that electric bicycle riders, like pedal bicycle riders, do not need to have a driver’s license opens up important mobility options for children and older adults, among others,” argues Agrawal. “However, I don’t think the legislature intended for children or people who have never studied the rules of the road to have access to a device that, quite literally, gives them the power equivalent to a horse.”

Other specific recommendations for the state include:

• Revise the procedures that medical staff and police officers use to report incidents involving two-wheeled electric devices to accurately distinguish legal electric bicycles from other two-wheeled electric devices.

• Minimize local variation in rules on riding electric bicycles so that the public can be reasonably expected to know what the rules are.

• Consider creating a legal pathway for high-powered electric devices by modifying the definition of mopeds to include them. With that change, the high-powered electric devices would require extra safety equipment, like turn-signals, and riders would also need a driver’s license.

• Expand safe bicycle infrastructure to respond to the finding that a majority of electric bicycle fatalities nationwide involve a crash with a motor vehicle.

ABOUT THE MINETA TRANSPORTATION INSTITUTE

At the Mineta Transportation Institute (MTI) at San Jose State University (SJSU) our mission is to increase mobility for all by improving the safety, efficiency, accessibility, and convenience of our nations’ transportation system. Through research, education, workforce development and technology transfer, we help create a connected world. Founded in 1991, MTI is a university transportation center funded by the US Department of Transportation, the California Department of Transportation, and public and private grants, including those made available by the Road Repair and Accountability Act of 2017 (SB1). MTI is affiliated with SJSU’s Lucas College and Graduate School of Business.

ABOUT THE PRINCIPAL INVESTIGATOR

Asha Weinstein Agrawal, PhD, is Professor of Urban Planning at San José State University. Kevin Fang, PhD, is Associate Professor of Environmental Studies, Geography, and Planning at Sonoma State University.

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