Three longboarders are in hospital after two separate collisions in West Vancouver and the Sunshine Coast.

A 19-year-old man is in critical condition after sustaining extensive injuries when he collided with a vehicle while longboarding in Madeira Park, Sunshine Coast RCMP said in a statement.

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Longboards are legal under B.C. traffic laws, but some cities and municipalities ban their use on public roads. (District of North Vancouver)

"It is believed that the longboarder... was attempting to make a right turn onto Madeira Park Road when he struck an eastbound vehicle head on," said Cpl. Steven Chubey in a statement.

The Madeira Park man was airlifted to Vancouver General Hospital, he added.

Later in the afternoon in West Vancouver, two long boarders were going downhill in the British Properties when they swerved to avoid an oncoming vehicle and crashed into a parked truck.

The driver of the vehicle going uphill was in his legal lane, said a statement from the West Vancouver Police Department. He is co-operating with police.

The 21- and 23-year-old West Vancouver men are in serious condition in hospital.

Last week a 17-year-old longboarder was hospitalized with a severe head injury following a collision with a van. The boy, whose name has not been released, remains in intensive care.

In July 2010 a woman in her 20s died while longboarding down Mount Seymour Road in North Vancouver when she collided with a van.

Longboarding is a form of skateboarding in which riders descend steep hills using skateboards designed for the high-speed turns.

It is banned on some streets in the three municipalities on the North Shore, but critics say the $45 fine isn't enough to deter riders.

And West Vancouver Mayor Michael Smith says it's not easy to enforce the ban.

"These longboarders move pretty quickly, and they are usually younger people, and when they see an officer, they get off their board and take off," Smith said.