An accident closing one lane of traffic on the northbound carriageway of the M1 between junctions 4 and 5 is causing a knock-on effect in the surrounding area.

Queues are building up on the sliproad at junction 5 Watford from London and there are lengthy delays around Watford for traffic trying to get onto the M1 as queues build up southbound with drivers slowing down around the scene of the accident.