New data shows nearly 800 were caught on two of the busiest days of last year as thousands crowded into Glasgow for the parade of Olympic and Paralympic heroes and the Christmas lights switch-on.
In both cases there were extensive traffic restrictions in force.
Neil Greig, director of research and policy with the Institute of Advance Motorists, said: "If the traffic management system forced cars into the lanes then fines should be refunded."
Mr Greig, who is a member of the Scottish Safety Camera Programme Advisory Board and chairs the Publicity Committee of Road Safety Scotland, added: "Stories such as these mean trust is eroded and it looks like a money-making scheme."
Figures showed 368 fines were sent to drivers who used the Cathedral Street bus lane between 6am and 10pm on September 14 when a temporary traffic order was in place, closing North Hanover Street. It was the day when Glasgow held its Parade of Champions which ended in the city centre.
Two months later, on November 15, North Hanover Street was again closed and 429 fines were issued to drivers caught in the bus lane between 6am and 9pm. But it was revealed that, a day earlier, when there were no traffic restrictions, just 100 vehicles were issued with fixed-penalty notices.
More than 15,000 people packed into George Square to be part of the Christmas lights switch-on.
A council spokesman said: "Driving in bus lanes has always been illegal. There is a clear and constant reminder of the law – the bus lane marking on the road. Before going live with the enforcement scheme, we ran a month-long advertising campaign and it was covered in the press."
A Glasgow City Council spokesman added: "Nobody was forced into a bus lane. There were diversions, which the vast majority of drivers followed."