When the congestion charge started, it was a glorious vision of how a low-traffic London might look. So double it or triple it – or consider charging differentially based on the time of day. Ring-fence the money and spend it ruthlessly on cycling, walking and canoeing down the Regent’s Canal. Dare I say it, you could even up the subsidy for London’s public transport system, recognising that Tubes and buses function as a kind of public good. I’d also look at Singapore-style solutions (where cars drive on alternative days). It is beyond bizarre that in a crowded city where air quality standards are routinely breached, imposing your polluting Mercedes tank on everyone else is still somehow considered an inviolable right.