The Metro was originally conceived of during the early 1970s, incorporating much of the earlier infrastructure formerly used by the Tyneside Electrics suburban network, with some elements dating back as far as 1834.

Construction work began in 1974, the majority of this activity being centred on the building of new tunnels and bridges that linked with several preexisting conventional railway lines that were converted.

Under the Metro Flow scheme, announced in March 2020, works costing £103 million are to increase the service frequency from five to six trains per hour, reduce journey times and improve reliability levels.

[17][18] Three railway lines, totalling 26 miles (42 km) were to be converted into Metro lines as part of the initial system – these being the North Tyneside Loop and Newcastle to South Shields branch (both of which were formerly part of the Tyneside Electrics network), and a short stretch of the freight-only Ponteland Railway between South Gosforth and Bank Foot, which had not seen any passenger traffic since 1929.

[3] The converted railway lines were to be connected by around 6 mi (10 km) of new infrastructure, which was built both to separate the Metro from the existing rail network, and also to create the new underground routes under Newcastle and Gateshead.

[8] The new section of track, covering a distance of around 2.2 miles (3.5 km), continued along the alignment of the former Ponteland Railway, with two stations constructed at Callerton Parkway and Airport.

[11] Between Pelaw and Sunderland, intermediate stations at Brockley Whins, East Boldon and Seaburn were re-built, with a further three being purpose-built for the network, at Fellgate, Stadium of Light and St. Peter's.

The project, valued at £1.5 billion, aimed to extend the existing Metro network, including links to Cramlington, Doxford Park, Killingworth, Metrocentre, Seaham, Team Valley and Washington.

In addition to this, plans would see the introduction of street-running trams, river buses across the Tyne, and cable cars, linking 29 key corridors.

Each Metrocar was stripped down to its frame and built back up again, with the addition of improved disabled access, new door control systems, and renewed interiors, seating and lighting.

[42][43][44][45] The first Metrocar to receive refurbishment was 4041, the unit being named after former Gateshead Councillor and MP, Harry Cowans, in honour of his work in the 1970s, to help to secure the construction of the network.

[48] The third phase of Metro's All Change programme began in 2019, with the procurement of a new fleet of 46 (originally 42) units, designed by Swiss manufacturer, Stadler.

In July 2018, Nexus announced the beginning of work to construct the new Maintenance and Renewals Skills Centre, at Mile End Road in South Shields.

The original livery used at opening was cadmium yellow and white, in accordance with the colours used by the Tyne and Wear Passenger Transport Executive at the time.

[65] A mid-life refurbishment of the fleet, carried out in-house, took place between 1995 and 2000; a new livery was adopted consisting of red, green or blue bodies, with yellow front and rear ends, and triangles containing the Metro logo on the doors.

Each Metrocar was stripped down to its frame and built back up again, with the addition of improved disabled access and new door control systems, with renewed interiors, seating and lighting.

[74][75] Stadler was awarded a contract to build and maintain 42 five-carriage light rail vehicles in January 2020, with deliveries to commence in late 2021 and all trains to be in passenger service by 2024.

The new trains will feature next stop audio-visual information displays, Tube-style linear seating to increase capacity, wider doors and aisles, air conditioning, WiFi and charging points.

In December 2021, Nexus revealed that the Metro fleet had entered the final assembly phase at Stadler's factory in Switzerland and that the manufacturer is in the process of fitting the main interior components of the first of the new trains.

[78] During September 2022, Nexus released a video taken at Stadler's test track in Erlen of a unit moving under its own power for the first time, prior to beginning full trials.

[citation needed] During November 2008, Nexus invited potential bidders to declare an interest in a contract to run the operations side of the business on its behalf.

[85] In December 2009, DB Regio was named as the preferred bidder, with the contract for operating the system signed in February 2010, and the handover of the service taking place in April 2010.

Sunderland is only one of two stations in the United Kingdom where light and heavy rail services use the same platforms; the other is Rotherham Central, which since 2018 has served both Northern and TransPennine Express, and the Sheffield Supertram network.

[35][36] Despite the majority of stations being open to access, the Tyne and Wear Metro has the third-highest level of passenger income per year (£45.2 million in 2013/2014) of the eight light rail networks in England.

Non-folding bicycles are not permitted to travel between Callerton Parkway and Airport, between Manors and St James, or between Jesmond and Gateshead Stadium at any time.

It heads underground at Jesmond, and runs south through Haymarket, Monument and Central, before rising above ground to cross the Queen Elizabeth II Bridge over the River Tyne.

[3] The Tyne and Wear Metro is one of the few rapid transit systems in the world with a pretzel configuration, in which a line crosses over itself and trains pass through the same station twice at different platforms.

A number of Metro stations feature commissioned works by various artists, including:[114] There have been a number of proposals looking in to the possibility of re-opening the former Leamside line to Washington, including a 2009 report from the Association of Train Operating Companies (ATOC),[123] and a 2016 proposal from the North East Combined Authority (NECA),[124] as well as the abandoned Project Orpheus programme, from the early 2000s.

By 2020, proposals were being put forward to link the current network at Pelaw and South Hylton, with the International Advanced Manufacturing Park in Washington, using part of the alignment of the former Leamside line.

It will be evaluated by the North East Joint Transport Committee with the ambition to secure funding from the Government to cover the cost of the scheme, expected to be £745 million.