And drivers are now being warned the fines will start coming as council bosses plan to turn on bus lane enforcement cameras on Cleveland Street, North Bridge Road and Waterdale.
If the trend continued from the number of warning letters, the council could rake in as much as Â£500,000 a month.
Doncaster Council refuse to disclose the day the cameras were being turned on but said the devices would become operational from '˜early November'.
Coun Chris McGuinness, the elected representative overseeing the scheme, said one motorist has been caught 29 times.
He urged people not to drive in the bus lanes and added said the council '˜don't want to find anyone'.
But a report published by officers in August show sets a prediction of how much the council is set to make each year. The figure has not been disclosed and is deemed '˜commercially sensitive'.
The report added August said 'further locations' will be 'phased in at a later date'. In 2016, a council survey confirmed 'widespread abuse' of bus gates in Doncaster and the new enforcement measures will allow 'bus operators to better run their services'.
The council is also under pressure from the Government's Department for Environment, Food andÂ Rural Affairs due to emission levels on certain routes coming into the town centre.
Motorists will be issued with a Â£60 fine reduced to Â£30 if paid within 14 days.
Coun Chris McGuinness, cabinet member for communities, voluntary sector and environment, said: 'The bus lane cameras became operational in October and in less than one month over 8,000 motorists have failed to take heed of the warning notices. Amazingly, one motorist has been caught 29 times and another on 18 occasions.
'We have been issuing warning letters but some people are simply not getting the message. One motorist has even said he would continue to use the bus gates until he was fined. Â With that in mind we are left with no option but to start issuing fines from early November.
"We are appealing to drivers to do the right thing and use appropriate routes rather than take a short cut along dedicated bus gates and lanes.
'The bus lanes are clearly marked and are designed to improve bus travel, support emergency services, taxis and cyclists and most importantly improve road safety. There are ample warning signs for motorists as they approach these restricted areas.
'Please follow the rules of the road. We don't want to fine anyone. Please don't drive down the bus lanes.'