Pedestrians might be twice as likely to be hit by an electric or hybrid car than those powered by petrol or diesel, according to a new study published on Wednesday in the Journal of Epidemiology and Community Health. 

Researchers found that the average annual casualty rates of pedestrians is 5.16 for electric and hybrid vehicles and 2.40 for gasoline and diesel vehicles. They studied 32 billion miles of travel for electric/hybrid vehicles and 3 trillion miles of travel for petrol/diesel vehicles in Great Britain between 2013, when national data began including hybrid as a vehicle fuel type, and 2017. 

“More pedestrians are injured in Great Britain by petrol and diesel cars than by electric cars, but compared with petrol and diesel cars, electric cars pose a greater risk to pedestrians and the risk is greater in urban environments,” researchers Phil J Edwards, Siobhan Moore, and Craig Higgins write. Electric vehicles are quieter and thus harder for pedestrians to anticipate, especially in urban areas where background ambient noise levels are higher. 

The researchers found that collisions with pedestrians are three times as likely in urban areas than in rural areas. All around, road traffic injuries are the leading cause of death for children and young people.

The study, though, lacked data beyond 2017 due to an archiving error, and in nearly 1 in 4 of the pedestrian casualties analyzed, the vehicle type code was missing. Yet the study adds a useful data point to the ongoing debate over the safety of electric cars amid the shift away from fossil-fueled in an effort to reduce air pollution.