A �1.4m project to cut down on lorry traffic in two Cornish towns by making a bridge passable is starting.
The road below Skew Bridge road will be lowered by 2m to reroute lorries away from Par and St Blazey, and give them access to Par Docks.
The work will see the A3082 closed for around 20 weeks. The cost of the project is being shared by the county council and shipping firm Imerys.
Roadwork traffic lights will operate under the bridge.