Motorists in Corsham have been warned to expect significant delays when maintenance work starts on two bridges.
Road bridges at Notton Lane and Ladbrook Lane are to be closed by Network Rail, as part of the electrification of the Great Western Railway, with traffic diversions in place for three and five months respectively.
Robin Basu, of Network Rail, said: “We need to make sure there is enough room for electrification lines to pass under the bridges, as part of work from Maidenhead to Cardiff.
“We are working really hard to minimise the disruption, but you can’t make an omelette without breaking a few eggs.
“The end benefit is electrified trains which are greener and faster, with more capacity and requiring less maintenance.”
Both bridges will close next month, with diversions in place.