[1] The overall responsibility for public transport in Trondheim is managed by Sør-Trøndelag county municipality, who subsidize the operations.

[2] Trondheim is also unique in that it is one of two rail lines in Norway built to metre gauge 1,000 mm (3 ft 3+3⁄8 in) (along with the heritage railway Thamshavnbanen), and since the closure of the Cairo tramways in 2019 is the only tramway in the world to use 2.6 m wide cars in combination with metre gauge.

The horses trotted between Buran and Ila via the city center until 1901, and transported more than 400,000 passengers in the peak year.

In 1900, the city council decided to establish a municipally-owned power and tramway company, Trondhjems Elektricitetsværk og Sporvei.

The coach company went bankrupt the year after, failing to make money on a route to Øya.

In 1918, eight used horse-cars were bought from Oslo Sporveier and rebuilt to electric trailers and to metre gauge.

To create enough overnight space for all the new trams, a third depot was built at Dalsenget, and the Elgeseter Line extended there in 1923.

Bakke Bridge [no] was rebuilt in 1928 so the last part of the Lademoen Line had double track.

[7] After a study trip to the United States in 1916, Director Fredrik Kleven made the observation that wider vehicles were in use there.

He brought the idea back to Trondheim, and the company made a policy to increase the distance between the tracks of a double line to allow wider 260 cm (100 in) cars to be put into service.

The first stretch to be opened was from St. Olav's gate to Munkvoll on 18 July 1924, after construction work lasting seven years.

After the war new investments were made, including loops in the city (1946) and at Lian (1947), double track from Breidablikk to Nordre Hoem (1948) and a new depot and workshop at Munkvoll in 1953.

The second half of this stretch was the only part of the tramway system built as single track and to be not located in the street.

[12] At night on 10 October 1956, the Dalsenget Depot caught fire, destroying almost all of the modern tram fleet.

Though the Conservative mayor, Axel Buch, was expected to be re-elected, Kristiansen chose to support the Labour candidate Olav Gjærevoll, in the hope that a socialist majority would ensure the future of the trams, and thus making Gjærevoll mayor.

The first time the decision was taken in the council, SV chose to support the closure, preventing two of its members from voting against.

The city council decided at the same time to build a new depot at Munkvoll and purchase 11 new trams, at a cost of NOK 100 million.

But the compromise also meant that the least robust part of the tramway was to be discontinued, thus the only line to survive was Lian-Lade.

In 1989 there was another mayoral election for the city council, and Bylista chose not to support the present mayor Per Berge [no] (Labour) and instead chose to support the Conservative candidate Marvin Wiseth, who was willing to allow a private company to operate the trams.

[18] Advocates of the trams have suggested expanding the tramway from its present terminus at St. Olav's Gate through the city core to Trondheim Central Station or Nedre Elvehavn onwards to Brattøra and Trondheim Port [no].

Estimates of costs lay between kr 50 and 80 million, with completion in 2009 at the same time as Nordre Avlastningsvei [no].

A plan to extend the network by building a line from Munkvoll to the new Byåsen Upper Secondary School[19] was dropped in 2004 after heated political debate.