Induced demand is a thing, make driving less convenient, and more people will take the tube/crossrail/bus. There are plenty of examples of successful pedestria

Induced demand is a thing, make driving less convenient, and more people will take the tube/crossrail/bus. There are plenty of examples of successful pedestrianised shopping streets, e.g. Stroget in Copenhagen, Buchanan St closer to home in Glasgow, La Rambla in Barcelona. Doing some rough measurements in Google Maps, Oxford St is roughly the same width (if not slightly wider based on the samples I measured) than La Rambla. And our weather is marginally better than Cophenhagen and Glasgow, so one can't attribute success only to nice weather.