Emergency crews responded to a vehicle collision on Roger Stevens Drive, between Rideau Valley Drive and River Road, just before 8 a.m. Saturday. The Ottawa Fire Department says the vehicle veered off the road, overturned and landed on a tree. Firefighters managed to remove the trapped driver from the vehicle and transport him to the ambulance. Paramedics tell CTV News Ottawa that an adult man was taken to hospital in critical condition. Roger Stevens Drive is closed between Rideau Valley Drive and River Road, and police are investigating.