One of Boris's pet schemes is to remove traffic lights to 'smooth traffic flow'. This is not the smartest of his ideas. Many of the lights suggested for removal are pedestrian crossings. The full list is here.
Now, putting in a pedestrian crossing is a very expensive business (£35,000) so most of them are in place for good reason. Removing a crossing or playing around with the timings obviously disadvantages vulnerable road users, but much more importantly, it is a safety issue. Long light cycles encourage people not to wait for the lights to change and instead take a chance with a gap in traffic. A misjudgement could be fatal.
Take for example, the three crossings on The Avenue, by Clapham Common, which - unbelievably - are all on the list. At peak times it is impossible safely to cross The Avenue without aid of a crossing, as traffic is very heavy and there are no natural interruptions to the flow. Many, many cyclists use these crossings as two of them form part of LCN Route 3. Given that they are part of a major cycle route, you would hope they would have special status. That said, it's not just cyclists: all these crossings give access to Clapham Common for children on their way to school, and for leisure purposes to pedestrians, runners, other sports people and dog-walkers.
I have little idea what playing with any of these crossings will achieve. The Avenue itself is not a bottleneck. The 'flow' problem is at the junctions at either end of The Avenue, with the A3 and A24. Improving 'traffic flow' - and hence eliminating gaps in the traffic - will make it more difficult and dangerous for any vehicle attempting to enter or exit the side-roads, and increase the buildup of traffic at the A3 and A24 junctions.
More here and here.