M.P. McQueen

Car sharing, the newest way to rent a car, is catching on in the U.S., Canada and Europe. But both renters and the car owners they rent from may be taking on risks they don’t fully understand.

At least one fatal accident involving car sharing has already occurred, resulting in litigation over financial responsibility. In February 2012, the 24-year-old driver of a car rented from one of the so-called peer-to-peer rental companies caused an accident in Boston, injuring four other parties. The driver died in the crash.

All four surviving parties sued the estate of the driver who died and caused the crash as well as the car’s owner, a former Google systems administrator named Liz Fong-Jones, and RelayRides, the peer-to-peer company which arranged the rental, according to William Doyle Jr., the attorney for Kevan Knecht, one of the injured passengers. After some legal wrangling, the four cases were settled out of court for an undisclosed amount, said Doyle, who is based in Boston.

The dispute over the RelayRides accident in Boston illustrates one big caveat about using car sharing services: Most state insurance laws haven’t yet caught up with this relatively new industry. Insurers and legal experts suggest drivers, and those who lend out their cars to peer-sharing services, should check their insurance coverage before using the services.