Pedestrians and bicyclists have ended up in more crashes with quiet hybrid cars than with typical vehicles with noisy internal combustion engines (ICE). The new National Highway Traffic Safety Administration report, titled "Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles", studied crashes between pedestrians/cyclists and vehicles finding that the lack of noise for new hybrids was linked to an increase in crashes. These crashes were more prevalent at intersections, interchanges, parking lots and other places where cars traveled at slow speed, the places where the hybrids were most likely to be quietest. It found that hybrids were twice as likely to be in a crash with a pedestrian in these areas.
According to ConsumerReports.org:
NHTSA looked at state-level crash files to compare crash rates on these two types of vehicle engines. Out of 8,387 hybrids 77 (or .9 percent) were involved in crashes with pedestrains. Out of 559,703 conventional vehicles studied, 3,578 (or .6 percent) were involved in crashes with pedestrians. In crashes involving bicyclists, 48 (or almost .6 percent) were involved in crashes with a hybrid vehicle whereas conventional vehicles were implicated in 1,862 (or .3 percent) of crashes.
The study (pdf) found that these incidences were more likely to occur in areas with low speed limits. The hybrids had a higher incidence—two times more likely to have a pedestrian crash—when they were slowing or stopping, backing up, or going in or out of a parking space. Most hybrids employ their electrical motors only at these situations, making these cars eerily quiet. However, there was no difference in rate of pedestrian crashes between these two vehicles when they were going straight.
In 2007, there were 70,000 pedestrians injured and 4,654 deaths due to crashes. A number of organizations, including the National Federation for the Blind, are pushing for legislation that would require all hybrid and electric vehicles to emit a sound. A number of car makers are looking into warning systems, as well.
In the meantime, hybrid drivers need to be aware of their stealthy approach and use extra vigilance and possibly look into installing a backup alert warning device or even a backup camera to be able to see pedestrians and bicyclists around their vehicle. Likewise, pedestrians need to be vigilant as electrified automobiles will become increasingly common.