THE M4 is expected to be especially busy on Saturday May 4 when those travelling to Badminton are joined by football fans heading to Cardiff for the football cup final.

Police are advising motorists to allow plenty of time for their journeys over the holiday weekend.

"We are anticipating heavier traffic than normal. It will be particularly busy westbound in the morning and eastbound in the evening," said Chris Silvanus of the Swindon traffic division, which is responsible for the Wiltshire stretch of the motorway.

He said congestion is particularly likely around junction 18, the A46 Bath to Stroud road, as motorists leave the motorway to head for the Badminton Horse Trials.

He did not think towns near the M4 would be noticeably busier than usual unless any incidents forced the police to divert traffic off the motorway.

He added that the motorway is still an efficient way of travelling, and did not recommend finding alternative routes.

Tim Peffers of Malmesbury Police said the area would have more traffic than usual, but that a change in the system at Badminton, allowing cars on to the site before paying, would lessen congestion. "Generally speaking there is a larger volume of traffic going through that area and there is a knock-on effect," he said.

Police in Gloucestershire are expecting tailbacks around the horse trials and have advised drivers where possible to find alternative routes.