Researchers from University of California San Diego have found that injuries involving electric bicycles, or e-bikes, have increased dramatically across California, rising from just two reported collisions in 2018 to 1,506 in 2024. The study (titled: An Exponential Increase in e-bike Injuries in California), published on July 17, 2026 in Trauma Surgery and Acute Care Open, also found that e-bike riders were more likely to experience moderate-to-severe injuries than riders of traditional bicycles, highlighting growing public health and safety concerns as e-bike use continues to expand statewide.

One of our most concerning findings was the disproportionately high number of injured children involved in e-bike crashes. E-bikes provide valuable transportation and recreational benefits, but their higher speeds can generate crash forces more comparable to motorcycles than traditional bicycles, leading to potentially severe injuries. Families should understand these risks, ensure riders wear properly fitted helmets and provide appropriate supervision and training. Safety education needs to grow as quickly as e-bike adoption and safety is our target for trauma injury prevention and advocacy."

John Austin, MD, general surgery resident and research fellow at UC San Diego School of Medicine and first author of the study

E-bikes have surged in popularity in recent years because they allow riders to travel farther and faster with less physical effort than traditional bicycles. While this growth has expanded transportation options for many people, researchers say it has also introduced new safety challenges. E-bikes are generally heavier and capable of higher speeds than conventional bicycles, factors that may contribute to more serious injuries when collisions occur.

To better understand injury trends, researchers analyzed data from the California Highway Patrol's Statewide Integrated Traffic Records System, examining collisions involving e-bikes and traditional bicycles from 2018 through 2024. The analysis included 4,035 e-bike collisions and 58,332 traditional bicycle collisions, making it one of the largest statewide studies of e-bike injuries conducted to date.

Key findings include:

  • Reported e-bike collisions in California increased from two in 2018 to 1,506 in 2024.
  • E-bike riders were younger than traditional bicyclists, with a larger proportion (15.6% vs. 10.2%) of injured riders 14 years old and younger.
  • Moderate-to-severe injuries were more common among e-bike riders than traditional bicyclists.
  • While overall mortality rates were similar during the study period, researchers observed a significant increase in e-bike-related deaths in 2024.
  • E-bike riders were more likely to be involved in violations related to unsafe speeds and improper turns.
  • E-bike collisions were more likely to occur in more affluent communities than traditional bicycle collisions.

Researchers say the findings suggest that e-bike injuries represent a distinct and growing public health challenge, one that may require safety measures tailored specifically to e-bike riders rather than traditional cyclists.

"E-bikes are here to stay, and they provide substantial benefits to mobility and recreation," said Jay Doucet, MD, voluntary clinical professor of surgery at UC San Diego School of Medicine and professor of surgery at Florida State University at Lee Health. "However, our study found a dramatic increase in e-bike injuries across California, including a disproportionate number involving children and low rates of helmet use among injured riders. Parents need to understand what they are buying for their children, and communities and policymakers need to recognize that safety infrastructure, education and policy have not kept pace with adoption. As trauma surgeons, we will continue our advocacy efforts to ensure that the benefits of e-bikes are realized while reducing preventable injuries and deaths."

Researchers say the results support efforts to improve rider education, encourage consistent helmet use and expand infrastructure designed to protect cyclists. They also point to the potential value of policies that address issues such as age requirements, e-bike classification standards and safe riding practices.

Future research will focus on linking traffic collision data with hospital and trauma records to better understand the specific injuries riders sustain and which prevention strategies are most effective. Researchers also hope to evaluate how emerging safety regulations and infrastructure improvements influence injury rates over time.

"As e-bike use continues to grow, it will be important to identify which interventions have the greatest impact on preventing serious injuries," Austin said. "Our goal is not to discourage e-bike use, but to ensure that riders of all ages can use them as safely as possible."

Additional co-authors on the study include: Louis Perkins, MD; Laura Haines, MD; Leslie Kobayashi, MD; Allison Berndtson, MD; Jessica Weaver, MD; Jarrett Santorelli, MD; and Amy Liepert, MD, from UC San Diego. Romeo Ignacio, MD, from Rady Children's Health and UC San Diego. Sigrid Burruss, MD, from UC Irvine. John Maa, MD, from MarinHealth Medical Center. Todd Costantini, MD, from University of Minnesota.

Source:

Journal reference:

Austin, J., et al. (2026). An exponential increase in e-bike injuries in California. Trauma Surgery \& Acute Care Open.DOI: 10.1136/tsaco-2025-002099. https://tsaco.bmj.com/content/11/3/e002099