One of the westbound lanes of the TransCanada Highway in Bonshaw was closed Saturday after a car went off the road and flipped several times.
RCMP said two men and two women, all in their 20s, were travelling from Moncton to a P.E.I. music festival.
Their car crashed and ended up about 150 feet into the woods.
All four people in the car were taken to hospital in Charlottetown. One man and one woman were taken by ambulance, while the other two were taken by RCMP.
RCMP said the injuries are not believed to be serious.
"It could have been a lot worse than what it was. Thank God it wasn't. I've seen a lot less for a lot worse," said Kirby Wakelin, chief of the North River Fire Department.
"I'd say they were coming down and because of the corner on the TransCanada here they just lost control of it."
A lane of the highway was closed for some time so crews could pull the car from the woods.
The lane was expected to reopen to traffic late Saturday afternoon.