The ‘flat railway crossing’, close to North Gate Station, is the last of its kind in Britain and is being upgraded this bank holiday weekend.
The works, part of a £1.2billion East Coast Upgrade by Network Rail, mean that all lines will be closed around Newark whilst the work takes place.
There will be a replacement bus service from Nottingham to Lincoln and from Newark North Gate to Lincoln on Saturday and Sunday, with operators advising to travel on Friday evening and Tuesday where possible.
Most LNER trains are diverted between Doncaster and Peterborough over Saturday and Sunday, and will not be calling at Lincoln. Replacement buses will run between Retford and Peterborough via Newark and Grantham.
On Saturday and Sunday, all Grand Central services are cancelled and Hull Trains services will be diverted to run to and from London St Pancras.
The current crossing system has been criticised by business leaders in Newark as a cause of delays and lengthening journey times.
The flat crossing system means that trains currently have to wait where the East Coast Mainline crosses the Nottingham to Lincoln line for other services to cross, which can take up to 20 minutes.
This also means there is a limit to the capacity of the rail network around Newark, and operators have been unable to expand the services they offer.
National Rail had previously said there would be no improvements to the line until 2030, the current project aims to transform travel to and from London Kings Cross and hopes to create capacity for up to 10,000 extra seats a day on long-distance services.
People planning to travel over the bank holiday weekend are advised to check their journeys online in advance to avoid delays.