As part of the Great North Rail project the 157-year-old stairs and bridge will be strengthened and the steel will be grit-blasted and fully repainted.
The Grade-II listed Victorian structure was originally built in 1863 - six years after the station opened.
Regular maintenance has kept the railway crossing in good condition over the years but the bridge is now in need of a complete £450,000 restoration.
Tom Syddall, scheme project manager at Network Rail, said: “The footbridge is a key historic feature of the station.
“Our restoration work as part of the Great North Rail Project will ensure it remains safe and reliable for decades to come.
“I’d like to thank passengers for bearing with us and using diversions while the much-needed work takes place.”
Chris Jackson, regional director at Northern, said: “The station is a significant part of the community and the work being carried out will not only secure the future of the bridge - it will ensure the heritage of the area is maintained.
“We’re working to keep disruption to our customers to a minimum but there will be some pedestrian diversions while the work is ongoing.”
The footbridge will be closed until the end of March to complete the important improvements.
No trains will be disrupted while the work is carried out.
A diversion for passengers between platforms will be in place during the project.