A cement mixer containing 12 tonnes of concrete has overturned on a roundabout.
Police were called to the incident at 1.49pm this afternoon (July 20) at the junction of the A41 and Two Waters Road in Hemel Hempstead.
A spokesman for Herts Police said the driver is believe to be uninjured but the road has been closed while the vehicle is recovered.
Motorists have been advised to avoid the area.
Highways have been called to deal with a damaged lamp post.