Californian Police have confirmed a Christchurch man was driving on the wrong side of the road when he crashed head on with another car in the US earlier this week.
James Sayer pulled out into the wrong lane from a scenic lookout in Toulumne County, three hours inland of San Francisco, around 6pm local time on Wednesday, the California Highway Patrol said.
"Sayer is used to driving on the opposite side of the roadway and turned left from the Don Pedro Lake Vista Point into the westbound lane," the CHP said in its collision report.
Driving a Dodge caravan, he crashed head on into a Chevy van that was travelling close to 100km/h.
Mr Sayer, 43, was travelling with Helen Celia, 37, and Ethan Sayer, three-years-old. All three were wearing their seatbelts.
Mr Sayer and Ms Celia walked away from the crash but were flown to hospital with "major injuries", while the three-year-old suffered minor injuries.
The driver of the Chevy, 59-year-old Californian man Edward Kalen, was pinned to his seat, the CHP said, and had to be pulled out by the fire service.
Mr Kalen was also taken to hospital with "major injuries".
The CHP said alcohol is not believed to be a factor in the crash.
The Ministry of Foreign Affairs and Trade says those involved in the crash are British citizens and they are receiving consular assistance from the UK.