A Parliamentary safety group is urging London Mayor Boris Johnson to hold a safety summit following the spate of cyclists' deaths in the capital. There was "a need for urgent action", said the Parliamentary Advisory Council for Transport Safety.
Britain's most senior police officer has warned that large vehicles can be "killing machines" and cyclists can find themselves in the path of a lorry or bus with "one wobble" in the wake of a spate of bike deaths.
Metropolitan Police commissioner Sir Bernard Hogan-Howe said drivers and cyclists need to think about how they use the road.
Speaking on LBC 97.3, he said: "We've all got to think about the way that we drive and the way that we cycle. It is difficult for the drivers.
"They're big vehicles, they can't always see out properly but they've got to take a little bit more care. When you've got such a big vehicle, then obviously they can be killing machines".
The unlicensed events unfolded on Saturday night at Clapham Common and Tooting Bec Common.
A 37 year old man who was taken to hospital after getting into difficulty in a stretch of water near Maidenhead has died.
Jonty Bravery, who is mentally ill, has been jailed for 15 years after throwing a six year old boy from the Tate modern balcony.