The work on the metal fencing at the junction between St John's Street and Cann Hall Road is set to begin on November 2 and last three days.
While contractors are on site, St John's Street will be closed between 9.30am and 4pm.
Councillors had been working to arrange the repairs but a change in contractors and lengthy price quotations delayed the process.
The area around the red temporary barriers, which now feature as a permanent fixture on Google Street View, was cleared and tidied by Kier in preparation for the repairs.
Residents had initially reported the damage taking place in 2015, but Shropshire Councillor for Bridgnorth East & Astley Abbotts, Christian Lea, said the incident in which a vehicle crashed into the railings occurred in June 2017.
Councillor Lea added: "Local residents will welcome the news that work to replace the damaged railings at the entrance to St John’s Street is set to get underway on November 2.
"This will greatly improve the appearance of the main gateway into Bridgnorth from Low Town, where the temporary barriers have been in situ for three years now, and which has not given a positive impression for anyone visiting Bridgnorth.
"Residents have been continually raising their concerns with myself and Councillor William Parr over the amount of time that it has been taking to get these railings replaced. It is really great news that at long last new railings are set to be installed.”
At the annual meeting of Bridgnorth Town Council in March 2018, Shropshire Council said the railings would be replaced by the end of June 2018, but work was stunted when the authority's highways contract with Ringway came to an end later that month.