First Science has a fascinating article evaluating the merits of the bicycle compared to other modes of transport in London:
Perhaps the biggest hindrance with public transportation is the problem of rising to the challenge of expanding urban populations and a corresponding demand for access to city cores. In recent years, our planet passed a critical mark – more of us now live in cities than in rural areas. Mass urban transport schemes such as subways, or those which operate on the surface or elevated tracks, groan under the strain of rush-hour peak demands.
The author's arguments for increased bicycle usage in London are strong, though in order for bike growth to really occur in the capital there needs to be increased investment in infrastructure to support the extra users.
LondonUnlocked has argued repeatedly that the Mayor and TfL need to invest more in cycle routes throughout London, and to rethink the bendy-bus strategy. To take the strain of our roads and public transport, cycling has to be a key element in any transport plan.