Drivers usually to blame for collisions with cyclists - study

Crashes between cyclists and motorists are usually the motorist's fault, according to a new study.

Researchers in Queensland analysed nearly 5400 collisions involving cars and bikes over a 12-year period, and found almost 46 percent occurred at intersections with 'stop' or 'give way' signs, 36 percent at intersections with no signs at all and 18 percent at traffic lights.

"In most cases, the bicycle and motor vehicle were approaching each other at right angles and possibly collisions occur because drivers have difficulty with judging gap sizes and speed before deciding whether to enter from the minor road or perform a  turning manoeuvre, said researcher Rabbani Rash-ha Wahi of the Queensland University of Technology.

He found 64 percent of all crashes were the driver's fault, which in his words, "hardly surprises anyone who rides". About 94 percent involved cyclists going straight ahead and getting hit from a car coming from the side.

This is because motorists are more likely to travel through an intersection "at high speed" if they think they've got the right of way, for example at a green light, regardless of whether cyclists may still be crossing after narrowly beating the red light.

"The large number of bicycle motor-vehicle crashes at four-way intersections with traffic lights suggested that cyclists may not have enough time to cross the intersection before motorised cross traffic receives a green light, possibly because signal timing is often based on motor-vehicle speeds," says Mr Wahi.

At intersections without lights, Mr Wahi's research suggests they're more likely than cyclists to drive straight on through without slowing down or stopping first.

But on the rare occasion that it's the cyclist's own fault, they're more likely to be hurt severely.

"When cyclists were judged to be at fault in crashes at stop and give way signs and uncontrolled intersections, their injuries were more severe," said Mr Wahi.

But it's not because they've been drinking - only 1.6 percent of the cyclists involved in accidents in the study were intoxicated. According to the Ministry of Transport, nearly 30 percent of fatal crashes in New Zealand are caused by drunk motorists. They're also to blame for 10 percent of minor accidents.

Another contributor to cyclists' serious injuries was hilly land.

"It may be that cyclists and drivers can't see each other until too late because of the crests and dips, or that they were travelling faster."

A recent transport forum recommended lowering speed limits to 30km/h in areas where cycling is common.

The Government is considering new rules that would fine drivers who get too close to cyclists.