This remained separated from the rest of the system until North Bridge was built to carry traffic over the Great Northern Railway main line to Edinburgh.

Soon afterwards, deep mining of coal began in the area, and several extensions to the system were made between 1913 and 1916 to serve new communities which developed around the pit heads.

The Racecourse route was unusual, in that it had balloon loops at both ends to enable almost continuous running on race days, a feature that was not common in England, and only found favour in Europe in the 1950s and 1960s.

From 1913 to 1919, the tramways were reasonably profitable, but suffered from lack of maintenance during World War I, and the poor construction methods used to lay the track.

The system had been financed by loans repayable over 40 years, and with the track needing replacement after half of that period, it was uneconomic to carry out the work.

One single-deck vehicle was purchased second-hand in 1917 in an attempt to reduce costs on the unprofitable Avenue Road route, but local crews would not allow one-man operation, and it saw little use.

Public transport in Doncaster began in 1887, when an undertaker called J G Steadman started running horse buses in the town.

However, in 1898 a more serious contender appeared, when British Electric Traction proposed tramways serving Avenue Road, Balby, Bentley and Hexthorpe, and began applying for permission to build them.

A hearing took place in Doncaster in February 1899, at which the Great Northern Railway objected to a level crossing with their line from London to Edinburgh.

Construction of the standard gauge 4 ft 8+1⁄2 in (1,435 mm) network began in 1901, and in order to cut costs, the foundations were not made as substantial as they should have been, resulting in ongoing problems with the track for years afterwards.

The Council borrowed money to fund the scheme, with the loans to be paid back over forty years, which was a longer period than the life expectancy of the track.

Another short branch from St Sepulchre Gate to Oxford Street opened on 25 November 1903, but was not profitable, and closed after two years.

These did not include the connection of the Bentley route to the rest of the system, which was authorised as part of the powers obtained in 1908 to build North Bridge.

This period saw the development of deep coal mining in the area, and the extensions were to serve new communities that grew up around the pit heads.

The plans for the tramway had envisaged single track with passing places, but it was realised that this would be inadequate particularly for the Racecourse route, which saw tens of thousands of people needing transport to and from the races.

The 1902 Order had also allowed a siding to be built beside the stands, and although most of the route was double track, the section at the bottom end of High Street was not, as it was too narrow.

The vast crowds of St Leger Day in 1902 showed that getting trams to the Station Road terminus under these conditions was almost impossible, and the 1903 Order sought to address this issue.

[4] They obtained powers to run their own motor buses in 1922, and purchased their first six vehicles from the Bristol Tramways and Carriage Company.

[8] The trams on the Avenue Road route were replaced by motor buses on 1 May 1925,[4] and the service was extended to Wheatley Hills at the same time.

[8] However, the Corporation took the decision in 1926 to replace the trams with trolleybuses, and obtained powers to convert their lines to this new form of traction.

[9] The powers were enshrined in the Doncaster Corporation Act 1926, and Clough, Smith & Co. were contracted to modify the overhead wiring.

On 15 January 1930, the Racecourse and Hyde Park services terminated, and in March 1931, trolleybuses replaced motor buses on the route to Wheatley Hills.

In 1922, West Yorkshire County Council announced that it intended to relay the road at a higher level, and this would have involved moving the tracks.

For the opening of the system, 15 trams were acquired from the Electric Railway and Tramway Carriage Works of Preston, which were mounted on Brill 6-foot (1.8 m) 4-wheeled trucks.

[23] In January 2013 it was announced that a proposed trial of Tram-train's linking Rotherham's Parkgate with Sheffield could lead to a similar scheme being rolled out in Doncaster.

[24] The extension of the Sheffield Supertram network to Rotherham using tram-trains was officially a Department of Transport experiment to prove the concept.