More than 100 vehicles have been damaged in one city alone by rising bollards like those installed in York this week, it emerged today.

The system of rising bollards - designed to restrict the flow of traffic to certain city centre streets - has caused "a lot of heartache" to highways chiefs in Cambridge.

And the council in Cambridge has had to go to "extreme lengths" to prevent further accidents.

The Evening Press reported yesterday how a taxi driver in York was injured when his car collided with one of the newly-installed bollards in Stonebow.

The obstruction had been installed on Monday to prevent all traffic except registered buses and taxis driving towards Pavement.

But Cambridge's example shows that the cab could be the first of many to be damaged.

Richard Preston, of Cambridgeshire County Council, said there had been more than 100 recorded incidents involving vehicles colliding with rising bollards since 1992.

"We have had to go to extreme lengths to stop this, including putting up a forest of signs, but people still run into them," he said.

Mr Preston said most incidents were caused by "the sheep mentality" and drivers tailgating other vehicles.

"If drivers drive with due care and attention and if the signing is adequate, people won't run into these things," he said.

"But there are plenty of people who don't do this."

Mr Preston said that public reaction to the rising bollard system in Cambridge had been mixed.

"It has given us a lot of heartache, but the bottom line is they are effective in enforcing traffic restrictions."

A York bus driver, who has recently worked in Cambridge and who asked not to be named, said he had personally witnessed "numerous" incidents where vehicles had been damaged by rising bollards there.

In one, a four-year-old child was thrown against the car windscreen and in another, a motorcyclist was hit, he said.

The bus driver said that it was invariably visitors to the city from out of town, who were following buses, who were involved in the incidents.

Meanwhile, York highways chiefs are monitoring St Saviourgate to ensure it does not become a "rat run" as a result of Stonebow bollards.

Peter Evely, head of highway regulation at City of York Council, said a consultation exercise had been held in the St Saviourgate area before the changes came in because of concerns that it might become the focus for new traffic pressures.