A crash on the M1 is causing delays this evening.

The collision has happened on the northbound carriageway between j6A for the M25 and j7 for Hemel Hempstead.

All lanes reopened at around 6.30pm - one lane has been shut by traffic officers, according to Highways England.

There are tailbacks of 10 miles on the M1 stretching back to j4 with travel time around 45 minutes. 

Delays should now begin to clear.

The M25, A414, A405, A4008 out of Watford, and Watling Street in Park Street were all affected as drivers sought alternative routes.

It remains very slow on the M1 northbound between Watford and the crash scene but delays on the M25 at j21 have cleared.

The A405, A414, and Watling Street into the Park Street roundabout remains slow and should be avoided.