A Kent MP has called for the cost of the A21 widening scheme to be reviewed after the project was postponed for at least five years.
The £125m project to dual the road between Tonbridge and Pembury in Kent was one of 14 put on hold by the government until at least 2015.
Conservative MP for Sevenoaks, Michael Fallon, said he believed the delay could be prevented if the cost was cut.
The widening scheme aims to cut delays and increase safety.
Construction had been expected to start in 2012.
On Tuesday Transport Secretary Philip Hammond announced which road and bus improvement schemes, currently in development, would get the go-head following the coalition's spending review.
Mr Fallon said: "There are problems with this scheme, it is incredibly expensive this scheme, you know £100m for 4km (2.5m) of road.
"We're not going to get the road in the next two or three years so I think there's plenty of time to look at the costs again.
"I think everybody would prefer to have a cheaper scheme rather than having this more expensive scheme be continually postponed."
About 40,000 vehicles use the stretch of the A21 every day, which has led to increased congestion in recent years.
Much of the route, which passes through Kent and East Sussex, is single carriageway.
The A21 improvements are supposed to provide better access to Tunbridge Wells and include a new flyover linking the A21 to local businesses and Pembury Hospital.
Five Kent and Sussex MPs have campaigned for the widening scheme, saying the work was vital to coastal regeneration around Hastings.