Orlando Street bridge reopened on Friday after work to improve it was completed.
The road can now hold 40-tonne heavy good vehicles – previously the bridge had a three-tonne weight limit.
The bridge closed last year to allow Network Rail to rebuild a large section of it in preparation for the introduction of new electric trains.
When Network Rail’s work finished at the end of March, the council’s contractors moved on site to carry out strengthening work to the last section of the bridge near Manchester Road.
This section of the bridge was in the council’s ownership, and the work was essential in order for the bridge to hold 40-tonne heavy good vehicles.
Bolton Council’s Executive Cabinet Member for Environmental Services, Cllr Nick Peel, said: “I’d like to thank drivers and local businesses for their patience while this project took place, and I’m pleased that the bridge has now reopened.”