Construction of a combination of the core sections of the original Line 1 and Line 2 is underway. 

Line 3 was intended to connect the city centre to Cameron Toll and onwards to major locations including the new Royal Infirmary of Edinburgh, a new Bio Medipark at Little France, new housing in Greendykes, and Fort Kinnaird before terminating at Newcraighall Station Park and Ride. Integral to Line 3 plans was the potential to extend the line to Musselburgh.

The route for Line 3 was considered the best for south-east Edinburgh in terms of meeting transport objectives. This area will see major development and will need significant improvements in transport to improve access. It will also provide new employment opportunities, assist in encouraging regeneration and enhance existing local communities in the south-east of the city.

A public consultation on the route of Line 3 was conducted in 2004 and a report detailing the results was submitted to the City of Edinburgh Council which included a final route alignment. This was approved by the City of Edinburgh Council on 11 November 2004.

However, plans for Tram Line 3 were shelved due to a lack of funding.  It is hoped that the current construction project is only the start of an integrated network, and that it will form the basis of future extensions, with the possibility of ‘Line 3’ being delivered in the future.