Mayor can't back up claim that two-thirds of cycling injuries caused by cyclists breaking law

Despite repeated requests, neither City Hall nor Transport for London has substantiated Mayor Boris Johnson's claim that two-thirds of serious cyclist crashes took place because the cyclist had broken the law.

The Mayor's claim is strongly at odds with previous data, which shows that when adult (aged over 24) cyclists were involved in serious collisions between 2005-07, the motorist was most likely at fault in around two-thirds of cases (see graph above).

Chief executive Ashok Sinha said, "Saying the majority of cyclists are responsible for their own injuries, contrary to the evidence, contributes to a culture that excuses motorists who drive badly, and undermines the strong case for increasing investment in safer cycling infrastructure." 

""If the Mayor can't show his figure is correct, he should set the record straight and acknowledge that, in the majority of cases, collisions that seriously injure cyclists have the responsibility attributed to the motorist."

Speaking at Mayor's Question Time on Wednesday 23 May 2012, Johnson said (after 2:31.40):

"I've seen a figure, I think, of 62%, which is the high proportion of cycling KSIs that are associated with some infraction by the cyclists themselves of the rules of the road."

[KSI = killed or seriously injured] 

His claim is at odds with the Transport Research Laboratory (TRL) figures, which are based on police reports of the causes of collisions between motor vehicles and bicycles.

According to the TRL study, only in crashes involving children and under-25 adults were cyclists predominantly at fault, although there's no record as to whether these cases also involved the law being broken.

The TRL study found adult cyclists shared resposibility with the motorist in about one in ten collisions, and were solely responsible for only a quarter of cases (but, again, there's no implication the law was broken).

These figures are backed up by a 2010 Transport for London study (the table on p22) that found motorists were responsible for crashes nearly three times as often as cyclists:

Attributed to cyclist 1860 times

Attributed to motorist 4796 times

* the figures above are for the main three causes: (1) not looking properly, (2) failing to judge another's speed/direction, (3) carelessness or recklessness

The Mayor's unsubstantiated claim came in response to a question from Conservative Assembly Group leader Andrew Boff, in which the latter claimed only "a tiny minority" of cyclists stopped at red lights on his way to work.

Only last month, the London Cycling Campaign was forced to respond to Addison Lee chairman John Griffin, who similarly claimed that the poor behaviour of cyclists is the chief cause of collisions, despite a lack of evidence.

In 2008, Johnson was filmed riding through six red traffic lights on his way to City Hall, and the Evening Standard found cars and motorbikes, as well as cycilsts, routinely disobeyed red lights.