A cyclist had to be airlifted to Derriford Hospital, Plymouth, with neck and head injuries after being in collision with a car on the Dawlish Road, Teignmouth.
The incident, which occurred just before noon, caused traffic chaos and police described the road as 'gridlocked'.
Vehicles were diverted to Exeter Road and New Road until the scene was cleared at 4.10pm.
Police, paramedics and the air ambulance all attended.
The cyclist, who is in his 50s and is from Somerset, was in collision with a Toyota Rav 4 registered to a Teignmouth address.
"The casualty sustained a serious neck injury and was stable," said a police spokesman.
"The incident attracted big crowds of people wanting to know what was going on."
