Fines for misusing bus lanes are overtaking parking tickets as the main cause of complaints from drivers, according to the AA.

The motoring group said thousands of drivers were being "entrapped" by worn road markings and poor signage.

A junction in Lambeth, south London generated the highest number of fines, totalling over £6m, the AA claimed.

The Local Government Association said strict guidelines were already in place and drivers could appeal against fines.

The number one complaint was drivers wanting to turn left who inadvertently merge into the bus lane early for safety reasons and are then caught on camera in the bus lane before they are allowed to be, the AA said.

It also received complaints from drivers pulling over to allow emergency vehicles to pass receiving tickets.

Fines go to the local authority and can be up to £130 in London - and up to £70 elsewhere in the country - with the sum halved for early payment.

'Lucrative rat traps'

Edmund King, AA president, said: "Whilst we support the use of bus lanes in the right places, functioning at the right times, we are totally opposed to 'entrapment' cameras on poorly designed or poorly signed bus lane junctions.

"If thousands of drivers are getting tickets at the same junction then something is wrong and that junction or bus lane should be reviewed.

"We fear that too many local highway authorities have become addicted to the lucrative income from these rat traps."

The organisation is calling for an official investigation to be launched when fines from one bus lane exceed £10,000.

The Department for Transport said the design, operation and enforcement of bus lanes were the responsibility of the local authority while the LGA disputed the AA's claims saying there was "scant evidence" to back them up.

A spokesman said: "Councils enforce the law to ensure bus services run smoothly. Motorists have a right to appeal if they feel they have been unfairly fined. However, just 0.5% of bus lane fines are appealed."