Quiet-running hybrid cars would appear to be no more dangerous to pedestrians than their petrol counterparts, according to new research by Queensland insurer RACQ.
The tests were undertaken in response to fears that the powertrains of hybrid vehicles such as the Toyota Prius are sometimes too quiet for unwary pedestrians to hear.
The concerns have prompted companies like Lotus and Nissan (for its Leaf electric vehicle) to develop audio systems that direct sounds ahead of the vehicle to warn pedestrians of its approach.
RACQ’s Steve Spalding said the study tested the ability of pedestrians to detect hybrid and petrol vehicles in real-world conditions, using hearing alone.
“Pedestrians rely heavily on hearing to varying degrees to identify the presence and speed of nearby vehicles,” he said.
“The results showed that while hybrid vehicles could be nearly silent, modern conventional engines are quiet enough that pedestrians have just as much difficulty detecting them in situations where there is traffic noise.
“Had the trial involved actual road crossings, many of the volunteers would have been struck by the cars.”
Carried out at a private course, the study used a series of recordings designed to replicate an urban traffic environment. With both blind and sighted but blind-folded volunteers, tests were conducted at speeds of 10, 20 and 60km/h to capture the hybrid and petrol engines in different stages of operation.
“The research found that 40 percent of volunteers failed to detect vehicles travelling at 60 kilometres per hour in time to avoid a collision," Mr Spalding said.
RACQ has not specified which hybrid- and conventionally-powered vehicles were used in the tests.