Obviously, 9 million people - but after a hectic day with 4 appointments, not me! The train (very expensive) in from Bath was 40 mins late, the tube (underground) was massively overcrowded, dirty and hot - and closed on the line I needed to use (electrical fault), leaving me and thousands of others exiting at the wrong stop. And the train out was standing room only for hundreds of us as for the first 40 minutes.
But, surprisingly, the taxi was cheap, and the driver friendly & fair, and the 'Cycle Superhighways' and 'Boris Bikes' (named after London's Tory Mayor Boris Johnson) were also cheap and easy to use - although I was very thankful I had a local cyclist 'guiding' me on the 4km ride we needed to make through the traffic. There are about 500 official bike docking stations, and over 6,000 hire bikes in the city, along with tens of thousands of other private bikes chained to bike racks, railings, posts and trees throughout the commercial area - sometimes I thought I was in Copenhagen!
I also visited the central traffic control room, where about 2,000 traffic cameras, dozens of operators, traffic police, utility and emergency service co-ordinators managed all the city's traffic - actually (and very efficiently) managing to keep it from grinding to a halt - one of the operators I met was a kiwi, so that was probably why!
All in all, however, competing with literally millions every day for footpath, road, and train space is definitely not your average kiwi's cup of tea. The fact that the London transport authorities have managed to get such a good (and growing) cycle network and infrastructure in place in the last few years is a testament to inspired political leadership, excellent staff management and clearly some community realisation that cars in such a crowded place are simply unworkable.