Velorution has an interesiting post commenting upon David Cameron’s cycling misdemeanours: Velorution: Safe Cameron.
this is the order of importance that should guide urban road facilities:
1. Safety of vulnerable road users, (pedestrians and cyclists)
2. Safety of motor vehicle drivers,
3. Convenience of vulnerable road users,
4. Convenience of motor vehicle drivers.
If a facility puts, say, the convenience of motorists ahead of the safety of vulnerable road users, it is reasonable to disregard it.