The Glastonbury Festival bought chaos to the roads around Shepton Mallet, but organisers say the problems were not all their fault.

Among the problems conspiring to make journeys around the area a misery for road users were a deer running loose on the site, which led to a gate being opened half an hour later than planned and contributed to a build-up of traffic.

Accidents on the M4 and A39 compounded the problem, causing chaos on major roads through the area, and problems in residential areas as festival-goers attempted to avoid the traffic jams.

By Thursday morning 90,396 people had arrived on site – up by almost 21,000 on the year before – adding to increased pressure on the roads.

And in the early hours of Monday morning, as fans left the site, they faced delays of up to five hours.

Crispin Aubrey, a spokesman for Glastonbury Festival, said he understood the frustration of people who had been caught up in the tailbacks, but said they had done all they could to keep traffic moving.

"No matter what steps we take, the roads in Somerset are narrow and not really designed for hundreds of thousands of cars turning up at once.

"When people arrive on site, we have to get them parked safely and make sure they can get their cars out after the festival is over," he said.

Traffic management was organised with the police and the festival had increased the amount of car parking available this year.

He said the festival had tried to encourage people to car share, come by coach or public transport and they would be doing the same for next year's event.

"We do everything we can to try and keep the traffic moving, but sadly, when the festival is on, local people will need to put up with some inconvenience, be patient, and use their knowledge of the area's back roads to get where they want to go."