Those on replacement buses heading to Manchester from Preston have less than a week more to endure.
Network Rail have announced the work at Moses Gate to repair damage caused by a burst water main is running ahead of schedule.
The railway bridge was badly damaged in mid-August when a section of it collapsed and created a hole in the road below.
Round-the-clock repairs mean the line between Bolton and Manchester should reopen on Wednesday 6 September.
Senior sponsor for Network Rail Andy Morgan said: “We have worked round-the-clock to repair the damaged bridge so we can get passengers back onto trains as normal between Bolton and Manchester as soon as possible.
“Repairing the water-damaged bridge has been a complex engineering challenge which included rebuilding a large section of wall which supports the bridge. Thankfully we have been able to fast track some of the work so Northern can run a full train service again from Wednesday 6 September.
“We continue to work with Bolton Council, Transport for Greater Manchester and United Utilities to safely finish the repairs and I thank passengers and local people for their ongoing patience.”
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Northern services have been seeing replacement buses take on the routes into Manchester.
Other routes to Manchester have been running via Wigan North Western.
Northern regional director Liam Sumpter said: “We look forward to welcoming customers back to Bolton on Wednesday as we restart a full train service for journeys into Manchester.
“We want to thank all of our customers for their help and understanding as we’ve worked through the challenges of the Moses Gate situation.”