Yesterday I observed an interesting public transport failure mode. Floods had closed many tube stations, so people took to the buses. The buses filled up. People making journeys that would otherwise have been unaffected by the tube station closures were left stranded as the full buses drove past their stops.
This situation should be a good business opportunity, but with all public transport in London provided by the same organisation, I doubt the incentives are strong for extra bus services to be laid on. No doubt taxi drivers did very well.