The M1 main carriageway has reopened following a "serious" crash involving a motorcyclist.

The crash happened on the southbound slip road at j8 near Hemel Hempstead.

Drivers cannot join the M1 at j8 in either direction.

Drivers travelling southbound cannot leave the M1 at j8 but drivers travelling northbound can leave at j8.

Emergency services were called at around 2.30pm and an air ambulance was called to the scene.

There are long delays in and around Hemel Hempstead.