The death of 4-year-old Ayden Fang in August of 2025 after an e-bike collided with a compact SUV that veered onto a Burlingame sidewalk is an enormous tragedy.
In the aftermath, the 19-year-old driver was not charged by the San Mateo County district attorney, who did not believe a jury would unanimously find the driver guilty. This decision was decried by safety advocates and community leaders with calls for greater accountability and justice.
I believe the case to be very complex. An 11-year-old was operating a Class 2 e-bike carrying a 10 year-old passenger and had the right-of-way. The impact of the e-bike with the SUV may have startled the driver into accelerating onto the curb. But in the interest of pedestrian, cyclist and driver safety, perhaps we need to think about ways to improve e-bike regulation and urban road design and safety, rather than trying to assign blame.
Similar accidents have unfortunately been reported around the world. German researchers noted car drivers underestimate the speed of e-bikes, and accept smaller gaps for crossing in front of them, relying on previous experience with conventional bicycles that travel at lower speeds. E-bikes look like regular bicycles from afar, but can close longer distances in the blink of an eye.
This tragedy could happen to anyone driving a vehicle — it was a disaster waiting to happen. But it would have been far less likely in Europe. The 2025 Mineta Transportation Institute report notes the “U.S. approach to defining electric bicycles rules is by no means common worldwide.” Almost all U.S. e-bikes would be illegal for sale as an e-bike in Europe, as the wattage of the motor is three times too high. American e-bikes would be regulated there as a moped, with a 15-year age requirement to operate and maximum speeds of 15.5 mph, with mandatory registration, licensure, insurance and education. New York City and New Jersey passed legislation incorporating these principles, and an 11-year-old will not operate a vehicle traveling 20 mph with a throttle alone there.
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My patient Amelia Stafford was the inspiration for Assembly Bill 1778 (Damon Connolly) that restricted class 2 e-bike use by riders under 16 in Marin as of July 2025. Assembly Bill 2234 (Tasha Boerner) took a different approach and requires riders one to be at least 12 years old to operate an e-bike of any class in San Diego. Both bills were originally introduced as statewide legislation, and either could have prevented the August Burlingame accident if they had not been amended to local pilot programs. This variation in laws across California is confusing. U.S. regulation lags behind other nations, and enforcement of existing laws needs to be strengthened. In 2002, Congress defined a “low-speed electric bicycle” as having a 750-watt motor and pedals, with a maximum speed of 20 mph, and by regulating it as a bicycle and not a motorized vehicle permitted use on sidewalks. It is noteworthy that Congress never specifically authorized Class 2 e-bikes with throttles involved in the Burlingame tragedy and a key problem nationally.
Local San Mateo County action followed after Ayden’s untimely passing. Assemblywoman Diane Papan, D-San Mateo, introduced Assembly Bill 1557 to implement a key Mineta report recommendation to limit all e-bikes to 750 watts of maximum peak power (instead of continuous power), closing a loophole that allowed increasingly powerful e-bikes to be marketed as street-legal. Many “750-watt” e-bikes currently deliver far greater bursts of power — allowing rapid acceleration and higher speeds that pose serious safety risks, particularly for youth. San Mateo County Supervisor Jackie Speier is preparing an ordinance to strengthen both rider and pedestrian safety.
According to the New York City Department of Transportation, bicycle deaths there reached a 24-year high in 2023, as 30 people were killed on a bicycle, 23 of which involved e-bikes (an estimated 20-fold increased risk of death after e-bike crash). The increased injuries have been partly attributed to bi-directional bicycle lanes on the same side of the street requiring one to look both right and left before entering the crosswalk, and allowing e-bikes on sidewalks where they are more likely to collide with pedestrians who cannot hear them approach as the electric motor is silent.
Fundamentally, from e-scooters to hoverboards to unicycles, e-bikes and self-driving cars — there are too many new vehicles competing for too little space in our crowded streets. Nothing can bring Ayden back, but his death can be a wakeup call. Perhaps one way to honor his memory is by fully analyzing the contributory factors to his death, following other nations and restricting the age of operation to 15 years, and redesigning our roads to prevent a repeat tragedy.
John Maa, MD, FACS, is a governor, American College of Surgeons.

(1) comment
Yes, make e-bikes safer, but why does the Dr. start the article referring to the case of a 19-year-old driver accelerating a 5,000 pound SUV onto a sidewalk, killing a four-year-old pedestrian? The PD has said that the e-bike drivers were doing nothing wrong, yet somehow their legal and appropriate behavior is used to start a discussion about e-bike safety. After blowing the e-bike dog whistle, he says this isn't about assigning blame, it's about making streets safer.
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