The Department for Regional Development (DRD) has been accused of running a "money-making racket" with the introduction of bus lane cameras to catch out motorists.
Drivers who stray into bus lanes from next month will be recorded on CCTV and issued with a hefty £90 fine.
Fixed cameras will be erected at six points in Belfast city centre to catch motorists illegally driving in the lanes. A mobile detection unit will also be deployed on the outskirts of the city and other towns where there are bus lanes.
The man behind the scheme, Ciaran de Burca, director for transport projects at the DRD, estimated that around 15,000 fines will be issued annually - more than 40 a day. This would amount to £500,000 in fines every year.
Mr de Burca insisted that the scheme was "not anti-motorist". He said it was about "making life safer and better for everyone".
However, DRD committee member David McNarry hit out at the scheme. "We can't keep punishing the tax-paying motorist," he said. "It's about time motorists were given a break. In fact, bus lanes cause the most congestion and should be withdrawn from service completely and an end put to all this nonsense."
The Ukip MLA added: "It's bad enough having to drive through Belfast without having to worry about cameras and fines. This is just a money-making racket, another tax on hard-pressed motorists. It will also be a visitor's nightmare. We are trying to attract tourists and then we'll just slap them with a fine if they stray into a bus lane.
"The DRD is using motorists as a cash cow. Motorists are being squeezed out of the city by buses and cyclists."
MLA John McCallister said visitors to Belfast can find the bus lanes confusing. "If we have bus lanes then of course we need to keep them clear but these lanes can be confusing, especially for visitors unused to driving in Belfast," he said. "We have to ensure people are not unfairly penalised."
The enforcement cameras will operate at Castle Street, East Bridge Street, Donegall Square East, Donegall Square South, Great Victoria Street and College Street East. A mobile camera unit will also enforce the bus priority measures across greater Belfast and in other towns with bus lanes.
Drivers detected illegally using a bus lane after June 21 will be issued with a £90 Penalty Charge unit. The fine will be reduced to £45 if paid within 14 days. There will also be a right of challenge.
Defending the scheme, Mr de Burca said that a recent survey showed that half of the vehicles using bus lanes were doing so illegally.
"The 90-95% of people who obey the rules will be very happy with this. There is frustration with people who drive down the bus lane while you are obeying the law," he added.
Money raised from the camera scheme, which will cost £200,000 to install and £100,000 to £150,000 to operate annually, will be pumped back into the transport system, Mr de Burca said.
Transport Minister Danny Kennedy said the measures would help ensure that "everyone who travels on our roads does so in a responsible and respectful way."
Belfast councillor Jim Rodgers said: "It is very frustrating for law-abiding motorists sitting in a lane and seeing a motorist drive past in the bus lane and getting away with it."
50kms: Total length of bus lanes outside Belfast city centre.
2kms: Total length of bus lanes within the city centre.
50%: Estimated proportion of vehicles which illegally use the bus lanes
1,000: Number of buses currently operating across Belfast
£90: The fine you will have to pay for illegally driving in a bus lane
£500,000: Amount expected to be raised through these fines annually