The Ford, which was only discovered by a hiker by accident last year at Dobie near Ararat, is believed to date back to the 1850s and is understood to have been used by heavy haulage heading to and from the goldfields.

The find has prompted calls for planning works on the duplication of the Western Freeway to be halted to excavate and protect the historical site.

But VicRoads said it has no plans to stop work on the road duplication, but will incorporate it into plans.

The hiker who found it, Roy Trimble said he believed the site had had up to five former bridges on it over the years.

“If you get to the road bridge and look over, you can see it,” Mr Trimble said.

“I was walking along over the grass and dirt and then all of a sudden I walked on something hard, I cleared the dirt away and there it was.”

Mr Trimble said he was documenting the site in a hope that it could be protected, having found no local historical record of its construction.

“There’s no protections on it at all, there’s no record of it having been there,” he said.

VicRoads North Western Roads Project Director Nigel Powers said VicRoads had brought in a consultant to investigate the heritage of the site.

He said Heritage Victoria had indicated that it did not intend to include the remains of the structure in its Heritage Victoria Inventory.

“We’ve put a lot of work into identifying and preserving areas of cultural heritage as we duplicate the Western Highway between Buangor and Ararat,” Mr Powers said.   

“Once this paved river crossing was identified, we brought in an expert to investigate and we’re now incorporating it into our plans.”

The site’s discovery is the latest in a long line of hold ups for the duplication project which has also seen Aboriginal community members  fight to prevent trees in the path being cut down. 

Elder Ted Lovett and indigenous women say there are at least five scar trees and three birthing trees in the area that could be lost should the duplication go ahead as planned. 

Also, in February last year, works between Ballarat and Stawell were suspended because VicRoads did not renew a planning permit for the project.