London's transport system is at capacity, not just roads but rail and air transport are all operating at 100% and can barely grow. So restricting transport furt

London's transport system is at capacity, not just roads but rail and air transport are all operating at 100% and can barely grow. So restricting transport further is politically difficult, for example, it is typically hard to actually get a seat on commuter trains due to overcrowding and my experience is that people frequently turn up to work late or miss trains because there is physically no space left on the transport system to get them to work. Given that, putting even more load on public transport by restricting vehicle traffic would be politically very difficult. Crossrail will help relieve the pressure along its route (10% capacity bump on rail!) but given the growth in the cities population and the possibility that the population figures are wrong anyway (the UK has not done a census for a long time), planners are anticipating that nearly all the added capacity will be used within just a few years. Hence them starting to plan Crossrail 2 before Crossrail 1 is actually finished.