THEY have been blighted by delays, controversy and contractual disputes, but by May 2014 Edinburgh's long-awaited trams should finally begin carrying passengers between the city centre and the airport.

The milestone comes seven years after construction work first began in 2007, when the original timetable predicted the trams would be up and running in 2011. The final cost is expected to come in at around £776 million, more than £230m over budget, despite only covering half the distance it was supposed to - from Edinburgh Airport to St Andrew Square instead of to Leith.

But with the countdown to completion under way, council owned company Transport for Edinburgh will operate the trams and are hopeful that locals and visitors will begin to forget the negative headlines associated with the project and embrace the new mode of transport, which brings the city into line with fashionable European neighbours such as Geneva, Vienna and Milan.

Although the start date is pencilled in for some time in May, the council has not ruled out launching the service even earlier in spring if it is ready.

City Transport Convener Lesley Hinds said: "The most up-to-date target is May for the service launch, but we've always said that if we could bring it in sooner than that then we will.

"We successfully tested the trams overnight two weeks ago along the full length of the route from the airport to York Place [in New Town] and back, and that went well. We're already running trams very regularly up and down the route between the Gogar depot and the airport for driver training because that section was handed back to Edinburgh City Council early in 2013. The second section to be handed over to the council was section B1, as it's known, between Gogar and Edinburgh Park station.

"That was handed over to us on December 17 and this means there are now three miles of track in the council's hands. The team at Edinburgh Trams are running around 150 trams a day to get drivers and the staff team trained, up to speed and ready for service."

The timescale for a full handover lies with contractor Infraco which still has to carry final tests and checks across the infrastructure. It has been checking everything from signalling and safety systems to the overhead power supply.

Uniforms and branding have already been unveiled, timetables are being finalised and all 32 drivers responsible for driving the fleet are in place. Once launched, the Spanish-made trams will run every 10 minutes off-peak and every seven and a half minutes in peak times.

A safety campaign is also set to be ramped up over the coming weeks, warning pedestrians and motorists to be aware of the new trams which can reach speeds of up to 42mph - though they will be restricted to existing speed limits in town.

For many, the sooner they begin running the better - if only to finally draw a line under one of Scotland's most bitter transport sagas.