The line has been in place for about 16 years
Work to upgrade track on some of Manchester's tram services has led to the closure of several stations.
Shudehill, Market Street, Piccadilly Gardens and Moseley Street stations are closed, with walking routes and buses for passengers set up instead.
Double trams will run between Bury and Victoria and between Altrincham and St Peter's Square every 12 minutes.
Metrolink said the work would make its services "smoother, quieter and more reliable".
Trams will also run between Eccles and St Peter's Square every 12 minutes.
The tram stops at Piccadilly Gardens and St Peter's Square will also be improved.