Roundabouts are risky places for cyclists, motorcyclists and pedestrians, according to research by Auckland University Master of Engineering student Nathan Harper.
Mr Harper recorded information about 95 urban roundabouts, ranging from simple single-lane intersections to the multi-lane roundabout at Panmure in Auckland.
Roundabouts had a lower injury accident rate than other intersectiontypes, including traffic lights, he said in a statement.
But cyclists, motorcyclists and pedestrians faced a significant injury crash risk at roundabouts.
Cyclists were involved in 24 per cent of injury accidents, with pedestrians in 15 per cent and motorcyclists in 10 per cent.
"These injury figures are disproportionate to the number of cyclists, pedestrians and motorcyclists who are on the roads. These users are more likely to be seriously injured in a crash, as they don't have the car to protect them in an accident," he said.
Cars entering roundabouts and failing to give way caused 45 per cent of injury accidents, with other accidents relating to loss of control (19 per cent), rear end crashes (16 per cent) and sideswipe crashes (5 per cent).
The research aimed to make roads safer by predicting which planned roundabouts would be susceptible to accidents.
The work, presented at transportation conferences in Wellington and Seattle, examined the geometry of the roundabout and traffic flows to predict accidents.
It could be used to build accident prediction models to fit in with a new funding model from road funding agency Transfund aimed at using accident prediction to fix problem areas before accidents happened, Mr Harper said.
His research is intended to be integrated with a major Government-funded research project in the United States to examine roundabout installation.
Roundabouts were a European concept and had largely been resisted in the US so far because of concerns for the safety of cyclists and pedestrians, Mr Harper said.
Roundabouts worked best in lower traffic flow areas and in situations without a dominant road.
Mr Harper works for the traffic engineering department at Auckland-based Opus International Consultants, which sponsored his studies as part of a bright future enterprise scholarship, administered by the Foundation for Science, Research and Technology.
Roundabout crashes
* Failing to give way caused 45 per cent of injury accidents.
* Accidents relating to loss of control caused 19 per cent.
