We don’t have to accommodate private motor vehicles in places like central London. The world wouldn’t implode if we did not; the economy wouldn’t collapse. We don’t have to accommodate any specific number of private motor vehicles in central London. We could choose to accommodate twice the number that we currently do, by bulldozing great corridors through houses, offices and public buildings, or by digging multi-billion pound tunnels and paving the parks for parking lots. We could choose to accommodate half the number that we currently do, giving what is currently road space instead to wider pavements and bus and bicycle lanes or street markets or cafes or flower pots or office blocks or docking stations or tramways or whatever we want to do with the scarce resource that is zone 1 land.