One aspect of safety which wasn't mentioned in the article is the moment when lights turn green and cars and bikes begin to move forward. There's a noticeable tendency for some riders to want to stay in front of the cars and this engenders an equally fierce desire in the drivers to overtake said cyclists. Road rage is almost unavoidable at this point.

I usually stop behind the lead car at traffic lights to avoid this; I can usually keep pace with cars (in London) but flaunting this by trying to race them away from the lights is just asking for trouble, not to mention more physically taxing.

So... if I'm on the front of a queue and can safely move away before the lights turn green, I'll do it because it puts distance between myself and the lead car, giving the driver more time to line up a safe manoeuvre around me once the traffic starts moving.

This has to be weighed up against the very real danger that the drivers will be fuming with rage at the arrogant cyclist in front and thus losing the senses of calm and serenity that I'm trying to spread :-)