Plans to pedestrianise Oxford Street within four years have been given a mixed reception by campaigners, who say City Hall needs to release more details.
London mayor Sadiq Khan plans to pedestrianise the stretch from Tottenham Court Road to Bond Street as part of his plans to tackle air quality.
And this week, London deputy mayor for transport Valerie Shawcross said City Hall hopes to complete the process by 2020.
Pedestrianisation will occur in two phases, with construction beginning on the section from Oxford Circus eastwards.
The chief executive of New West End Company Jace Tyrell said: "We look forward to seeing and discussing detailed proposals for Oxford Street following Ms Shawcross’s statements but feel very strongly that any form of vehicle free zones must lead to a genuine reduction of traffic, rather than large scale re-routing down smaller residential or commercial streets.
"In addition, it must be accompanied by a full economic assessments to measure the impact on businesses and the shoppers and workers that travel to the West End every day via public transport."
London First infrastructure director David Learn added: "Oxford Street is clearly not in a fantastic place at the moment. It has a wall of buses and taxis through the middle of it, and unless something radical is done it will punch well below it's weight," Learn says.
"But we need to see the detailed plans of how this will happen in practice. The mayor has set a very clear goal here. Now we need to see the hard work to make it happen."
Cars are already banned on most of Oxford Street between 7am and 7pm from Monday to Saturday.