Glasgow City Council placed a daytime ban on vehicles using the bus lane near Queen Street station in July.
A total of £800,000 worth of penalty charge notices (PCNs) have been handed out since the change was introduced.
Drivers who have breached the restriction face a £30 fine which increases to £60 if it’s not paid within 14 days.
Figures revealed that by September 1, at least 28,000 drivers had used the lane.
The ensuing fines have earned Glasgow City Council roughly the same amount in two months as Edinburgh and Aberdeen Councils receive from all bus lane transgressions in a year.
So far £477,000 in fines has been paid by drivers.
Now council chiefs are planning to look at how to improve signage to make sure drivers are aware after admitting the number of fines was unusually high.
But it has also denied that the bus gate is a source of income and said that the gate was put in place after consultation in order to improve the environment and the flow of traffic.
Last year, Edinburgh City Council received £718,000 from bus lane fines while Aberdeen City Council received £896,000.
Glasgow - Scotland’s largest city - received a total of £3,283,776.
The Glasgow Restaurant Association wants the city council to reconsider the Nelson Mandela Place restriction as it fears it is doing more harm than good.
The first full week of operation from July 5 until July 11 saw 4,759 PCNs issued.
And the most recent full week from August 15 until August 22 saw 3,859 issued - a drop of 900 tickets.
A council spokesman said: “It’s very encouraging that the number of drivers illegally driving through the bus gate has dramatically fallen since the gate went live.
“A like-for-like comparison of the latest full week figures and first full week of operation shows a drop of 900 contraventions - almost 20% - and we expect further reductions.
“The significant reduction in offences shows that the majority of drivers have now identified alternative routes they can take.
“The bus gate was introduced to reduce through traffic in and around Queen Street Station and provide a pedestrian gateway to George Square with the added benefit of improving the environment both for pedestrians and cyclists and making crossing this area more user friendly.
“It also delivers benefits for public transport users.”
The spokesman added that a total of seven permanent signs had been put in place to advise that the bus gate is operational on Hope Street, West George Street, West Nile Street and at Nelson Mandela Place.