A busy road in Bury St Edmunds will be restricted to one lane for at least 18 months while engineering work takes place.
Westley railway bridge, on Newmarket Road, needs strengthening after a structural assessment was carried out in May. Traffic will be restricted to one lane across the bridge with the use of traffic lights although the existing 7.5 tonne weight restriction will be lifted.
A spokesman for Suffolk County Council said measures would be put in place to minimise disruption.
He said: “We are currently in discussions with National Rail and our contractors to identify the exact extent of works and the necessary lead-in time needed, therefore the time scale is only an approximate at this stage. In carrying out these works we’re able to lift the 7.5 Tonne weight restriction currently on the bridge, allowing heavier goods vehicles to travel over it.”