It happened on the A377 just before 11pm on Friday night.
A silver Peugeot estate left the road and hit a granite post and some trees.
A 41-year old man was taken to the RD&E with serious head and chest injuries.
He was later transferred to Derriford Hospital in Plymouth.
Officers from the Serious Collisions Investigation Unit are investigating and appealing for witnesses.
North Molton storm overflows halved
Water storage tank added at treatment works
Devon County Council elections - all the candidates, all the wards, all the key dates
All the information you need
Exmoor Coaster service coming back under different name
'Explorer' subsidised by county councils
Bodmin Moor fires are suspicious
Police asking for help over blazes on Saturday
Storm overflow prevention work set for Plymouth
But it will take five years
Help needed to find Exminster pensioner
Concerns for Charles Fulton, 74
