Church Street is largely pedestrianised, yet Phil Simpson, director of The Sun Hotel & Bar, said traffic is still an issue and he fears an accident could soon occur.
He said the "constant stream of cars, motorbikes and push bikes has become both intolerable and extremely dangerous".
And he added that much of the traffic is caused by people using the street as a rat run.
"Apparently the bulk of Church Street is pedestrianised," Mr Simpson said. "Bars and restaurants have dressed the street with smart tables and chairs, the area has become almost continental in design...apart from the horrendous number of vehicles that steam down the road at all times.
"This has become a serious problem and I genuinely worry that someone will be injured or worse in the coming weeks.
"Hundreds of vehicles travel down this "pedestrians only" street every day and despite representation to city and county councils, nothing is being done.
"We see taxis dropping off customers, delivery drivers picking up their food items hourly, motorbikes enjoying leisurely cruises both up and down the road and the never ending parade of fast moving push bikes. It's anarchy.”
Mr Simpson said Lancaster Business Improvement District (BID) has also raised concerns, alongside many businesses.
"Seemingly this daily embarrassment to the city will only get attention when some poor soul suffers a serious injury," he added.
A Lancashire Police spokesman said: “We acknowledge the concerns of the public and do recognise an issue.
“A multi-agency review will take place to seek solutions to the issue.”
Peter Bell, regulation and enforcement manager for Lancashire County Council, said: "We regularly enforce parking restrictions on Church Street, which is always open to access for blue badge holders to be able to park, however the prohibition of driving restrictions are an issue for police enforcement."
A Lancaster City Council spokesman said: "We are aware of Mr Simpson’s concerns and that Lancaster BID is keen for the situation to improve. However, whilst the city council is supportive, it is a Lancashire County Council issue to resolve."