> In London some bike lanes have slightly increased travel times by car but cycling has increased more than 50%.

50% of anything near zero is still darn close to zero. But at the same token, a 5 minute increase for 1000 people is a loss of 5000 minutes.

> The reason people in cars don't notice bike traffic is because a bike is small and unobtrusive and silent.

False. A single bike sticks out like a sore thumb in traffic -- even if there's a bike lane. In this case, I was so pissed off at the increase of my commute I started to count bikes in the bike lane, and I saw exactly zero.