The Metro Flow project will see the dualling of three key sections between Pelaw and Bede stations – scheduled for September to December 2022 - creating capacity for an extra 24,000 Metro passenger journeys every day.
Transport chiefs say the £100 million will also increase metro frequency to one every 10 minutes outside central areas and improve reliability, as well as allow quicker recovery from major disruptions.
It is hoped the project will also unlock the door to expanding the Metro system.
Work has now started on the installation of the new overhead lines which will power the network on the new sections of track, once they are completed later this year.
A major line closure will be in place between Pelaw and South Shields from Monday, September 12, through to Thursday, December 5, when three sections of single track will be dualled.
During the closure, a replacement bus service will run in the affected area.
Metro Flow has secured £95 million worth of funding from the Government’s Transforming Cities Fund and Buckingham Group Contracting Ltd has won a £55 million tender for the construction stage.
The funding for the Metro Flow project has also financed four more new trains on top of the 42 already ordered.
Head of Metro Flow, Tom Hardwick, said: “This month marks a step change it the delivery of the Metro Flow project, which will transform Metro by allowing Nexus to increase the service frequency systemwide.
“Customers and our neighbours will start to see the delivery of the first of the new overhead line masts which will be installed in the trial holes currently being dug on site.
“While the majority of the works will be completed during two weekend closures at the end of June and beginning of July, followed by a 12-week major line closure in September, the team will be working every night when trains are not running in order to minimise disruption to our customers as much as possible.”