A piece of Bradford's transport history has been unearthed as workers dig in on a new £10 million improvement scheme.

Work to transform the Mayo Avenue roundabout into a crossroads, complete with state-of-the-art computer-controlled traffic lights, started in March.

One of the first tasks for contractors Mowlem plc was to dig out the existing roundabout for the new through road.

And as the diggers began clawing back the earth, workers unearthed old tram lines.

Martyn Binns, project manager with Mowlem plc, said the tram lines would have been stripped out of the rest of Manchester Road when it became a dual carriageway, but the section under the roundabout was left intact.

The lines have nothing more than scrap value, and workers are now set to dig them out to make way for the new road. "They wouldn't have built the tram line over a void," said Mr Binns.

But this is not the case for the rest of the site. Workers will have to make sure that there are no holes under the surface.

They will be able to test the firmness of the ground using the California Bearing Ratio Test - a metal plate which is pushed on to the ground under pressure to show the level of resistance.

The subways that criss-crossed under the road have all been closed off and replaced with pedestrian crossings.

A special concrete mix will be pumped into the passageways to make them solid and allow the 66,000 cars which use the road daily to pass safely over them.

When the work on the junction is completed, the 30-strong team will move on to Staygate roundabout.

This will undergo a radical change, with an extension to the northbound M606 and a new routing system around it.

Technical manager Martin Thornton said a new link road from Manchester Road to the Staygate roundabout should open in October.

"It will remove the traffic turning left from Manchester Road at the roundabout," he said, "In effect, the traffic going up to the roundabout should be reduced to vehicles either going straight on or turning right."