Network Rail is fitting three miles of new railway track in Craven Arms, and the company says it will keep the town's level cross open "as often as possible" during the work.
The work is being carried out in stages on a number of weekends, starting this weekend, and finishing on Sunday, November 21.
Originally, the level crossing had been planned to temporarily close for two months but, after concern from local businesses, Network Rail, together with the freight operators, has changed its plan.
The work will see the renewal of three miles of track that runs through Craven Arms station, on the Marches line, between Newport and Shrewsbury.
The road over Long Lane level crossing will be closed on a number of dates for the work.
A diversionary route using Clun Road and Watling Street will be put in place for smaller vehicles.
Larger vehicles will be diverted via the A49, A4113, B4385 and B4368.
Pedestrians will be able to access the crossing when work is not taking place on site.
Andrew Hayward, project manager at Network Rail said: “We have listened to feedback from local businesses and replanned our work to enable the level crossing to remain open for much of the project. We would like to thank local businesses and the local community in advance for bearing with us whilst we carry out this essential upgrade work.”
Philip Dunne, MP for Shropshire said: “I am pleased Network Rail have listened to concerns of local businesses and the community, and have worked to find an alternative to a lengthy closure of the level crossing at Craven Arms. This change will significantly reduce disruption, and will help maintain easier access to the household recycling facility for local residents, which I was keen to ensure.”
The main work will take place over four weekends in September and October.
There will be a rail replacement bus service in operation between Hereford and Shrewsbury whilst the work is underway.
Network Rail said it has also planned additional upgrade work at Ashford Bowdler level crossing on September 25 and 26 to coincide with the work at Craven Arms.
The dates for work in Craven Arms are as follows: 11pm, Friday, September 17, to 6am, Tuesday, September 21; 11pm, Thursday, September 23, to 6am Tuesday, September 28; 11pm, Thursday, September 30, to 6am Tuesday, October 5; 11pm, Thursday, October 7, to 6am, Tuesday, October 12; 11pm, Friday, October 15, to 5am, Monday, October 18; 11pm, Friday, October 22, to 5am, Monday, October 25; 11pm, Saturday, November 20, to 10am, Sunday, November 21.