Police in Norwich say they will remove those who act as human bollards to block Exchange Street.
It comes after a woman stood in the road on Saturday, November 5, in protest against those still driving on it during the pedestrianised hours between 10am and 4pm every day.
Lucy Hall, 66, from Norwich, said she got to "the end of her tether" and began blocking vehicles trying to illegally use the road, which was pedestrianised in June this year.
Following the incident police say they have carried out some enforcement on those who continue to use the road, but added current signage was "not adequate" due to the number of drivers still using the route.
A police spokeswoman said she was aware some officers had waved vehicles through the street and said they would be given suitable guidance.
She said: "We have raised our concerns with the highways team at Norfolk County Council who have reassured us they will be making improvements to signage to make it clear to motorists.
"In the meantime, we are in discussions around further alternatives to help to ensure a higher level of compliance.
"On Saturday officers dealt with a woman causing an obstruction of the highway which is an offence – and while cars shouldn’t be driving on the route – there are exceptions such as emergency vehicles on 999 calls.
"We will seek to remove people from the highway for their own safety."
Following the incident last week, Ms Hall said it was dangerous for cars to travel on the street during pedestrianised hours.
She said: "I was trying to make a point that it should be possible to stand in a pedestrian zone for a while.
"You might be talking to friends or catching your breath or checking your phone.
"The pavements on Exchange Street are often crowded and I'm currently using crutches so I use the road since it’s pedestrianised.
"But I always get drivers beeping and shouting at me. I’m fairly mobile but this is also a disability access issue.
"If an area is called a ‘pedestrian and cycle zone’ but drivers are using it at some speed then it’s dangerous.
"The police were a little heavy-handed. I was expecting them to have a word with the drivers rather than threaten to arrest me."
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