A new study conducted by Australia's Center for Automotive Safety Research confirms bull bars fitted on 4-wheel-drive vehicles increase the risk of serious injury to pedestrians.

The University of Adelaide center looked at the impact different bull bars have on an adult pedestrian's leg and a child pedestrian's head and found that, on average, all bull bars resulted in more severe injuries than a standard bumper.

Steel, aluminum/alloy and polymer bull bars were tested on six popular 4WD vehicles. Steel and aluminum/alloy bull bars performed much worse, while polymer bull bars gave better results in impact tests.

Robert Anderson, senior research fellow, says there are a number of reasons why polymer bull bars generally perform better than metal bull bars.

"The polymer bull bars are much lighter and not as stiff as metal bars, so in an impact with a pedestrian, they tend to give a bit more," he says.

Anderson says the study, the first of its kind comparing different bull bars and vehicles, was prompted by a lack of information on the level of risk to pedestrians.

"Really, what I'm targeting are the vehicles that don't see a lot of rural driving," he says. "If they're going to hit anything, it's more likely to be a pedestrian than a kangaroo."

In response to the tests, Pedestrian Council of Australia Chairman Harold Scruby is calling on state and territory governments to ban bull bars from all passenger vehicles as soon as possible.

"Governments which choose to pander to the bull-bar brigade and refuse to enact this legislation must be held responsible for the deaths and injuries which will follow," he warns.