Roadworks that have caused problems for motorists on Ipswich’s Norwich Road will now continue until the end of the month after workers found “engineering challenges.”

The work near Norwich Road bridge is being undertaken by infrastructure company Cadent which is replacing a gas main.

The junctions of Cromer Road, Kelvin Road and Lister Road on to Norwich Road have been closed and there are three-way traffic lights controlling vehicles and causing serious rush hour delays.

The roads should have been reopened last weekend and the lights should go by February 12. But the work has now been extended. The roads will not now reopen until February 19 and the lights will not go until February 26.

A spokesman for Cadent said there had been engineering challenges to overcome.

He said: “Unfortunately the work is taking longer than originally expected due to engineering complications with the job.

“Originally we had hoped to insert the new pipes into the old gas mains, a technique we regularly use and which requires minimal digging and can consequently be done quickly.

“However the special resin which has been used to fix gas leaks on the pipe over the years has taken up approximately 25 per cent of the mains diameter which has made inserting the new pipes impossible.

“Therefore we have had to dig open trenches in which to lay the new gas pipes.

“We did bring in a special trenching machine to try and speed up the digging of the trench – however Norwich Road is very robustly constructed with reinforced concrete under the asphalt.

“This wore out the 24 cutting teeth on the machine after only 5metres so we have had to revert to using larger machines than usual to dig the trenches and this is a very slow process.

“We’re sorry for any inconvenience people may be experiencing as a result of our extended work and we’re doing everything we can to complete the work as soon as possible – though the challenging conditions on the ground may cause further delays.”