Traffic in Adlington and Heath Charnock was brought to a standstill last week, with angry motorists stuck in long queues.
Chorley Road in Heath Charnock closed at Skew Bridge last Monday so that work could be carried out for the electrification of the railway.
But it led to traffic chaos in the area, with drivers facing long delays, particularly at rush hour.
Many have complained that the road has been shut at the same time as nearby Rawlinson Lane, also for the electrification work.
Both bridges are shut for five months and there are fears the problem could be exacerbated as Station Road, Blackrod, closed yesterday and Grimeford Lane, Blackrod, shuts next month.
It follows the closure of Railway Road, Adlington, for several months last year for work on electrifying the railway.
There were complaints about temporary traffic lights in Adlington, at the junction of Church Street, Market Street, Railway Road and Park Road.
These were believed to have contributed to the problem, although changes were made to the traffic lights towards the end of the week which reportedly eased the situation.
Five bridges between Chorley and Bolton are being rebuilt as part of a £1bn project to electrify the railway.
Ian Joslin, Network Rail’s area director, said rebuilding the bridges is “essential” and that it was not possible to complete one bridge at a time.
He apologised for the disruption caused.
A spokesman for Lancashire County Council said they had worked closely with Network Rail and contractors Carillion to improve things.
See today’s Chorley Guardian for a special report.