Roman artefacts have been discovered during a motorway upgrade job being carried out by Carillion and Morgan Sindall

Archeologists have discovered a Roman industrial estate during an upgrade of the A1 being carried out by Carillion and Morgan Sindall.

A 50/50 joint venture of the two firms is carrying out a £209m upgrade of the motorway, including adding a lane, between Dishforth and Leeming in North Yorkshire.

But because the road follows the path of Dere Street, an old Roman road, archaeologists were asked to carry out a year-long excavation.   

Today the Highways Agency announced the archaeologists have discovered coins, pottery and brooches, and what they suspect was a Roman industrial estate, near Dishforth. The site is believed to have some connection with the nearby Healam Bridge fort, which was built in the first or second century.

Blaise Vyner, who is working as a cultural heritage expert for Carillion and Morgan Sindall, will show the findings to the media at the site office in Northallerton on Wednesday.

The Carillion/Morgan Sindall started work last year and is due to finish in 2012.