Edinburgh's tram service has taken its first paying customers as the long-awaited route from the airport to the city centre opened to the public.
The first tram service set off at 05:00 from the Gyle shopping centre in the west of the city.
It follows six years of disruption and problems, including a bitter dispute between the council and its contractor.
The Edinburgh tram route cost £776m and covers 8.7 miles (14km) from the New Town to Edinburgh Airport.
In the decade since the first money was allocated to the project, the price has doubled, the network has halved and it has taken twice as long to build as originally planned.
Tram enthusiasts Marjory Broom, 59, her husband George, 63, and son Christopher, 31, were on the first tram as it went from the Gyle shopping centre to York Place in Edinburgh city centre, before heading out to Edinburgh Airport and then back to the Gyle.
Mrs Broom said: "It was chock-a-block, and it was a real carnival atmosphere on board, with people cheering as the tram set off."
She added: "We've been on trams all over the world and the tram in Edinburgh today was really, really smooth.
"It was the first tram and it was standing room only, it was very, very busy.
"I'm really excited we managed to get on - there would have been no buzz being on the second tram."
Also on the first tram was Edinburgh City Council transport convener Lesley Hinds, who conceded the transport project had been "hugely challenging" but said there was now "growing positivity" about the trams.
"Two years ago, I pledged to do everything in my power to ensure we brought this project in on the revised budget and revised schedule," she said.
"It was never going to be straightforward, but with an incredible team effort and a focus on results, it now feels fantastic to be where we are today."
The tram project was almost scrapped just weeks before the construction began in 2007 and later ground to a halt for months when the company in charge of the trams fell into a bitter dispute with the main contractor.
The people of Edinburgh suffered six years of disruption as roads were closed for construction and businesses have also complained it caused them to lose trade.
Edinburgh City Council chief executive Sue Bruce accepted the project had been a "shambles".
"It's not a day for jubilation," she told BBC Breakfast.
"I think the whole of Edinburgh is relieved that the programme is now in place and the city can move on."
She said there were "big questions to be asked over the original due diligence of the programme" and the council had to be "held to account" over what had gone wrong.
Edinburgh has 27 trams in its fleet, although only about half of these will be in service at any one time.
Tram vehicles, each costing about £2m, can take 250 passengers - 78 seated, 170 standing and two dedicated wheelchair spaces.
The full journey from the airport to York Place in the city centre should take about 35 minutes.
The route has 15 stops, three of which connect with rail and bus services.
The tram services will run seven days a week, with a reduced timetable on Sundays.
During the week, the first trams will run from the Gyle at 05:00 and from the airport at 06:15.
Trams will run from York Place to the airport from 05:29.
At peak times, the trams will runs every 8-10 minutes.
The last trams to travel the full route will leave from Edinburgh airport at 22:45 and from York Place at 23:08.
Tickets cost £1.50 for a single in the city zone and £5 for a single to or from the airport.
Operators warned passengers should get a ticket before getting on the tram as there will be a £10 fine for anyone travelling without a ticket.
It had been hoped the tram fleet would offer free wi-fi, but it is understood most carriages will be installed with internet access in the weeks and months following the launch date.
Original plans to take the tram line to Leith were scrapped but could still be implemented in the future.
Edinburgh City Council transport convener Lesley Hinds said: "You can't underestimate the amount of money over-budget and the time it's been over as well. Obviously that has been extremely frustrating and I think it's been damaging to the city of Edinburgh.
"Our purpose over the last two years has been to get passengers on the tram from the airport to York Place.
"We do have enough trams to go down Leith and we have the rails because that was all bought before.
"There will be a report at the end of the year to see how people are taking to the system and it will suggest how we might want to further invest in public transport and the trams come under that."
There have been calls for a public inquiry into the trams fiasco but Scottish Transport Minister Keith Brown said there are no immediate plans for one.
"We've said let's wait until the system is up and running and then look at lessons to be learned," Mr Brown said.
"I've spoken to the council already about this and will speak to them in future because the council has a number of legal actions ongoing and we can't have inquiries which cut across that.
"A total of £776m has now been spent on the system so let's make as much money as we can and get people on as many trams as we can to help repay that cost."