Highways contractors have been sent back to change speed bumps rebuilt on Bramford Lane in Ipswich last year because it was discovered they were the wrong shape.

Work started on Monday and is expected to continue until Friday.

The new work comes just a year after the bumps were re-built, but a survey discovered they ramps on either side were not at the right angle and had to be rebuilt.

A spokesman for Suffolk County Council said the work was being carried out at no cost to the authority because the contractors accepted that it had been caused by their mistake.

The road is being partially closed between 9.30am and 3.30pm – but should be open to traffic during the busiest times of the day.

However parents driving children to or from Springfield Infants or Junior schools have been finding problems.

If ramps have the wrong gradient then they can either fail to slow down the traffic – or they could damage the tyres of vehicles going over them.

Suffolk County Council cabinet member for transport James Finch said: “Safety of all road users and pedestrians is our absolute priority.

“We ask our contractors to reduce disruption associated with any work carried out on the highway as much as possible. In this case, no council tax payers’ money is being used to pay for this work.

“The contractor in this case acknowledged that revision was required to these speed bumps following their installation, and they are carrying out this work now, during off-peak hours to ensure the works meet our high specifications required.”

Members of the public told the Star that some of the ramps along the road had been too steep since the work was completed last year.

There was also irritation that the work had been carried out before the end of term, making it difficult to take their children to school.

However the disruption yesterday was limited because the work was carried out during off-peak times and most commuters heading to work were not caught up in any extra congestion.

The work is expected to be completed by the weekend which should allow traffic to use the road more freely.