More than 4,400 motorists were caught driving in bus-only streets in the centre of Oxford in the first month after enforcement cameras went live.
Some 4,480 drivers were fined a minimum of £30 for flouting cameras in the High Street, Castle Street, George Street and Magdalen Street.
The council said it equates to only a 10% drop in traffic passing through.
The fines have raised an estimated £135,000 for Oxford County Council, which installed the cameras.
Councillor David Robertson, the deputy council leader, said he was "disappointed" with the statistics "considering the publicity the council gave it".
Parking account
"We want to reduce the amount of traffic coming into the city centre," he said.
"The gates are there to smooth the flow for public transport.
"The cameras are working and people will be fined. But I'd rather people didn't drive through them than get fined."
The cameras went live on 26 March. Fines increase to £60 if not paid within 14 days.
Mr Robertson said the revenue raised would be put back into the council's parking account and if there was a surplus at the end of the year it would be spent on environmental schemes.