Could your electric car warn pedestrians of your approach with a Quiet Riot riff at 20 MPH?
Written by Donna Emert
Electric cars are quiet. Who knew that would be a problem?
Advocates for the blind and the U.S. government are among those who did.
In early 2010, the Pedestrian Safety Enhancement Act became law and required the National Highway Traffic Safety Administration (NHTSA) to set a minimum noise level for hybrid and electric cars.
Most electric car makers, including Nissan, are addressing the silence of electric vehicles moving at 20 mph or below, before it becomes a safety issue.
"They're getting out ahead of it," said Ben Barton, University of Idaho assistant professor of psychology and communication studies (pictured above). "They know with quieter cars there could be certain types of pedestrian at risk, particularly the visually impaired, children and those with hearing impairments."
Barton is one of a few safety experts in the nation whose research focuses on the psychological and behavioral aspects of driver and pedestrian safety. He has recently completed three Nissan-grant funded human factors research projects addressing automated noise for use in electric vehicles.
In one of those studies, Barton and University of Idaho psychology graduate student Nicholas Cottrell (Sandpoint, Idaho) prepared a review of artificial engine noise as a form of automation in cars. That study will soon be published in Theoretical Issues in Ergonomics Science.
The evidence they found suggests that providing an automated solution for drivers, rather than a manually operated device, is likely to decrease drivers' mental workload and stress, ultimately keeping both drivers and pedestrians safer.
Cottrell earned a U-Idaho master's degree in psychology last spring. The value of what he learned goes beyond academics:
"The human factors program has students conduct a practical thesis," said Cottrell. "Taking academic coursework and transforming it into a genuine application of your skills not only crystallizes the lessons learned in the classroom, but is extremely gratifying as well."
Barton and Cottrell's research will help Nissan and other car makers design safer electric vehicles. Its impacts and implications are global. For Cottrell, the impact of the research is also personal.
"Employers want both experience and education, and conducting field research is a fusion of these two," he said. "Telling an employer you took a class is fine, and something just about anybody can claim, but having a real, published piece of work which has contributed to the scientific body of knowledge is something else altogether. This demonstrates your education and ability in a very real way."
In additional research for Nissan, Barton has investigated how readily people recognize regular, combustion-engine produced sounds. That study looked at a sample of 50 children, ages six to nine, and 35 adults. He found significant differences in children's and adult's abilities to detect a vehicle's approach: Among the children in that age range, detection of vehicles and correct determination of directionality were less sophisticated.
"Results underscore the importance of auditory cues for pedestrian safety, particularly children's safety, and highlight the need for further research," he said.
Adding automated noise will not be necessary at high speeds, when velocity provides. But a soundtrack for stealthy, slow moving e-cars is already being developed.
"It was initially reported somewhere that the noise being adopted was going to sound like the car in ’Blade Runner,’ " said Barton. "That's not true."
The sounds adopted to make electric cars safer may vary, but Barton says he doesn't foresee the driving public downloading car noises like ringtones anytime soon.
"I can't say for sure it will never happen, but the noises that the car companies are using are noises in certain frequency ranges," said Barton. "They use high range frequencies, and lower tones, so that the greatest number of people can hear them. It's a good human factors solution."