The Stansted Express will be out of action every weekend from February 22 to March 23 between the airport and London Liverpool Street.
The specific dates the train services will not be running on are: February 22 and 23 and March 1, 2, 8, 9, 15, 16, 22 and 23.
These journeys should work out quicker than taking the express train, as the coach journey will take around 45 minutes compared the 48 rail trip.
The three routes are: the A6 from Marble Arch, the A7 from London Victoria Coach Station and the A8 from King’s Cross St Pancras.
National Express has also confirmed they are adding 25,000 extra sears between London and the airport.