POLICE have expressed alarm that motorists caught up in tailbacks on the M4 in Wiltshire decided to park up on the hard shoulder and do a spot of sunbathing on their car bonnets.

People who were stuck on the motorway following an accident thought a good way to spend their time would be to top up their tans.

But officers from Swindon traffic unit say the pastime is highly dangerous and they want to put a stop to it straight away.

They are urging drivers and their passengers to stay in their cars when stuck in traffic and not to be tempted out even if the sun is shining.

Police were called to a crash on the westbound carriageway between junctions 16 at Swindon and 17 at Chippenham on Saturday when they spotted people getting out of their vehicles to stretch their legs.

A white Nissan had lost control and hit the central reservation after trying to avoid a car, which had pulled out into its path, officers said.

The carriageway had to be closed while the accident was dealt with and long tailbacks lasted for around three hours.

Pc Andy Stanley, of Swindon traffic police, said he was shocked to see people parking on the hard shoulder and getting out of their cars.

He said: "This is very dangerous. The hard shoulder is the only way for emergency vehicles to get to the scene of an accident.

"If you do come across static traffic on the motorway drivers should not park on the hard shoulder and should remain in their vehicle."

He said several witnesses he had spoken to had seen people sunbathing on the bonnets of their cars.

The accident happened at about noon on Saturday when, it is believed, a maroon-coloured 4x4 or hatchback car pulled out into the middle lane of the carriageway, into the path of the Nissan.

Police said the female driver of the Nissan tried to avoid a collision by pulling out into the fast lane but lost control and hit the central reservation.

Her car flipped over and landed on its roof, and she sustained whiplash and a cut to her finger.

The driver of the maroon car had already left the scene by the time they arrived and they are keen to speak to them.

Police would also like to hear from any witnesses who saw the incident.

Anyone with information should contact Swindon police on 01793 528111.

Lyndsay Scanlan