Tram work diversions due to start in Edinburgh
Edinburgh Council's leader said the capital was "very much open for business" despite its main street being due to close to traffic for 10 months.
From 05:00 on Saturday, Princes Street will close to all vehicles for tram works, with buses, taxis and cyclists being diverted along George Street.
Cars and lorries will be diverted along Queen Street.
The diversions will be lifted on 24 November until January. The work is due to be finished by July 2012.
The work is to fix crumbling tarmac around the tram lines.
Jenny Dawe, the leader of Edinburgh City Council, said: "This is a first step in getting the works moving forward. We recognise the impact of putting the diversions in place.
"Disruption to visitors and shoppers on Princes Street will be kept to a minimum and we have liaised closely with local businesses to ensure the diversion goes as smoothly as possible for them.
"Our message is that Edinburgh is very much open for business and this will be communicated to the public through advertising, on-street signs and maps in the run up to the diversions going into place.
"The measures to avoid a clash with the very important winter festival season also remain in place."
Sue Bruce, Edinburgh City Council's chief executive, said: "It's essential for the project that we begin work soon, and for everyone in the city centre the certainty that it will be finished as soon as practicable is important.
"A huge amount of effort has gone into this and all parties are working hard to ensure we make headway for the short and long-term benefit of the city."
It follows the council signing a new deal with its main trams contractor, Bilfinger Berger, ending speculation over the future of the project.
The council confirmed a deal was agreed and signed following negotiations with Bilfinger Berger which lasted until the early hours of Thursday morning.
It also follows the Scottish government's announcement that Transport Scotland is to step in to help manage the scheme.
Ministers agreed to reinstate £72m of funding they had earlier withheld.
The trams are due for completion by summer 2014, at a cost of £776m.