A 64-tonne crane which has broken-down on the A361 North Devon Link Road has forced two lanes of the carriageway to be closed.
Police said the lorry suffered a snapped exhaust which caused some air pipes to melt resulting in mechanical failure.
The road is currently blocked in Bishop’s Nympton at the B3227 junction.
Recovery of the vehicle is not expected until around 5pm, meaning the road could still be blocked as commuters attempt to make their way home on the link road.
Officers remain at the scene and are redirecting traffic around the broken-down vehicle.
Motorists are advised to travel with extreme caution.