DOZENS of new ambulances costing a total of £4 million are off the road in North Yorkshire today - because they cannot cope with speed bumps.

The 40 Mercedes vehicles were bought last year by the Tees, East and North Yorkshire Ambulance Service Trust (TENYAS), but they have never been used beyond a small-scale test which threw up the problem.

The difficulty has been caused by the weight of the hydraulic lifts fitted to the back of the ambulances to get wheelchairs in and out of them.

The lift apparently makes the ambulances sit lower than they would otherwise do.

The vehicles then strike the road when driven over the traffic-calming road humps, which are a particularly popular speed control measure in the York area.

Earlier this month, TENYAS was branded one of the worst services in the country, according to government figures, after it was awarded no stars.

While the £100,000 ambulances await modification, the vehicles are being stored at stations across the region.

In the meantime, the service is having to rely on older vehicles which require more maintenance and spend more time off the road.

No one was available for comment from the health workers' union Unison today.

But the union is reported to have said that there were no staff representatives on the group that drew up the specification for the new ambulances.

Officials are said to contend that if they had been involved in the preparations, they could have brought up concerns about the humps, and the problem might have been avoided.

In a statement, TENYAS patient services director Tim Lynch said the vehicles were due to be modified.

He said that they should be on the road by the end of September.

Updated: 11:06 Wednesday, July 30, 2003