People are to be asked to give their views on plans for a tram system that will link north and south London.
The consultation will run until January 2007.
The Cross River Tram would run through the heart of the West End, linking Kings Cross and Camden in the north with Peckham and Brixton in the south.
Transport for London Commissioner Peter Hendy said the aim of the project was to relieve congestion on the Northern and Victoria Underground Tube lines.
The consultation is to help establish a preferred route.
Under the plans trams would arrive every two minutes at central London stops and every four minutes at outer stops.
They would run on separate lanes to all other traffic and offer a hop-on, hop-off service at the same cost as a bus journey.
Consultation is expected to start next week and will continue until January 2007.