Councils are making millions of pounds from company car and van drivers caught straying into bus lanes.

Last year, 984,000 people in England and Scotland were issued with penalty charge notices, worth an estimated £76 million.

However, some councils are continuing to issue tickets on stretches of road where drivers have successfully lodged appeals, when signs have been deemed inadequate or misleading.

Motorists that break the rules and enter a bus lane can face a fine of up to £120 in London and £60 outside the capital.

Less than 1% of drivers fined appeal against the notices, but reports suggest that 50% of those that do are successful.

When fines are appealed, an independent adjudicator will look at them on a case-by-case basis and its ruling is binding. However, its decision does not set a legal precedent and a council does not have to do anything apart from waive the penalty charge notice.

The AA told the BBC that “an adjudicator’s decision about signage must be acted upon by the highways authority” and it would be “ludicrous” to carry on collecting fines “without remedying the problem”.

Birmingham City Council has issued around 80,000 fines worth an estimated £4.8m after installing 10 cameras to police bus lanes in the city last September.

An independent adjudicator will make a ruling this week on 20 claims by motorists who say they have been fined unfairly for using those bus lanes because signage is inadequate.

The local authority said it believed the scheme was fair and that the signs met guidelines.

However, Councillor Tim Evans, who is a member of Birmingham City Council’s transport scrutiny committee, said: “Common sense tells you this is not right; our experience is it’s not right; 80,000 tickets is not right.”

Committee chairman Councillor Victoria Quinn also said a company car driver faced a £3,000 bill after 20 tickets arrived at once because an unnamed leasing company had added £45 to every charge.

Hammersmith and Fulham Council issues tickets amounting to £1m a year for contravening a bus lane in Shepherd’s Bush. It insists the lane is clearly marked and fully compliant, despite it being criticised by an adjudicator.

Councils in Medway in Kent and Camden and Harrow in London have also refused to make changes after adjudicators found their signage around bus lanes to be confusing, while Transport for London continues to issue tickets worth £13,000 a week on a bus lane where two adjudicators have said the signs are unclear.

However, last month Essex County Council waived £1m of bus lane fines issued to 30,000 people after it granted an amnesty to motorists who had used re-introduced bus lanes in Colchester town centre. It acknowledged bus signage and road markings were unclear, and has promised to make improvements.

Councillor Rodney Bass, cabinet member for highways and transportation at Essex County Council, said: “I have asked for additional signage and road markings to be installed as soon as possible to make it clearer to motorists where the bus lanes are located.”

In a similar move, Hertfordshire County Council refunded up to £1.3m after adjudicators labelled signage inadequate for a bus lane in Hemel Hempstead.

It had issued nearly 35,000 penalty charge notices in less than six months before deciding to pay back the fines.

The council said it wasn’t under a legal obligation to refund the penalties, but felt it was the right thing to do.

Company car and van drivers could be at an even greater risk of falling foul of the law in the future.

More bus lanes are being introduced in towns and cities to ensure public transport runs to time, and councils say the penalties stop motorists abusing the system.