A 13-tonne digger was knocked off a lorry yesterday in the latest incident involving a “problem” railway bridge.

Despite laser technology to warn lorry drivers approaching Kingway bridge, on the A429 south of Malmesbury, the digger hit the bridge and fell into the road at 8.45am.

The collision could have proved fatal if traffic had been travelling the opposite way when the digger landed on its side in the road.

Malmesbury Sergeant Martin Alvis, who was at the scene shortly after it happened, said: “The consequences could have been far worse had anyone been travelling by at the same time.

“The safety beam put in place on the bridge has done the job and taken the hit without causing much damage to the bridge.

“Trains were put on slow for about 45 minutes which created delays.”

The road both ways between junction 17 of the M4 and Burton Hill, Malmesbury, was closed for several hours causing long tailbacks, while a crane was used to lift the digger and turn it upright before it was secured to a recovery vehicle.

The driver, who is from the local area, was given a fixed penalty notice at the scene, with three points on his licence and a £60 fine.

Engineers from Network Rail inspected the train line this morning, but the bridge was found to be structurally safe and trains continued their usual operation. It is the latest in a series of crashes at the accident blackspot which, in 2007, resulted in thousands of pounds being spent on the installation of two interactive height warning signs in a joint initiative with Network Rail and Wiltshire Council.

Ian Henderson, chairman of Malmesbury Without Parish Council, said: “If a lorry has ignored the sign there’s not a wild amount that we can do about it; it’s just naughty.

“It blocks the road and it can often be blocked for some time; this is where it becomes difficult locally.”

Prior to the new laser technology being installed, 50 collisions at the bridge, stretching over a five-year period, are reported to have cost Network Rail more than £500,000.

Hullavington Parish Council chairman William Harmer said: “It has always been a problem and we believe that everything that can be done to ease the problem has been done.

“Every time it happens, there is a massive jam and there have to be diversions.

“It’s hard to understand how lorry drivers can be so stupid when all these measures have gone in to help them avoid going under.”