Some two million hybrid electric vehicles (HEVs) have been sold in the United States since commercial production began in 1999. Among the advantages typically mentioned are that hybrids are cleaner, more energy-efficient and quieter. However, one of these apparent benefits carries with it potential risks for other road users, who are accustomed to an environment dominated by louder combustion-engine vehicles (CEVs).

A 2009 National Highway Traffic Safety Administration report, “Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles” (PDF), investigated HEV accidents that involved pedestrians and cyclists. Analyzing more than 550,000 crashes across 12 states between 2000 and 2007, the study compared accidents to better understand the relative risks of HEVs and CEVs to pedestrians and cyclists on American roads.

The study’s findings include:

• For the 8,387 HEVs and 559,703 CEVs studied, a total of 77 and 3,578 pedestrians were involved in crashes with HEVs and CEVs, respectively. A total of 48 HEVs and 1,862 CEVs were involved in crashes with bicyclists.
• For accidents where a vehicle was slowing or stopping, backing up, entering or leaving a parking space (when the sound difference between HEVs and CEVs is most pronounced), HEVs were twice as likely to be involved in a pedestrian crash than CEVs.
• For crashes involving cyclists or pedestrians, there was a higher incident rate for HEVs than CEVs when a vehicle was turning a corner. But there was no statistically significant difference between the types of vehicles when they were driving straight.

Tags: bicycling, bicycle, bikes, cars, safety