An overturned trailer at Junction 18 of the M4 is causing delays of one hour. 

Highways England earlier tweeted about the incident, detailing how the trailer had tipped in lane one in the roundabout. 

It was carrying hay bales that are being cleared from the junction. 

An 'Up and Over closure' has been put in place at junction 18 of the M4 eastbound to facilitate the recovery of the overturned trailer and hay bales from the roundabout.

There is more than 4 miles of congestion back towards junction 19. With average speeds on the approach to Junction 18 just 6mph.

The eastern side of the roundbout heading south towards the A46 has also been closed.