Hybrid electric (HE) passenger vehicles first became available to consumers in 2000, and their numbers as well as their proportion of the passenger vehicle fleet have risen every year since their introduction. By 2009 the number had grown to comprise 0.6 percent of the passenger vehicle fleet. Advocacy groups have raised pedestrian safety concerns regarding HE vehicles because a vehicle using the electric motor may be relatively quieter than a vehicle using an internal combustion engine (ICE) and may not emit the sounds that non-motorists rely on for warning as vehicles approach.
In 2009 the National Highway Traffic Safety Administration released the report “Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles” with the finding that an HE vehicle was two times more likely to be involved in a pedestrian crash than an ICE vehicle in situations involving low-speed maneuvers (Hanna, 2009). This report aims to update the previous report with more data by adding additional years of State crash files as well as by increasing the number of States included in the analysis from 12 to 16.
This analysis was conducted on a total of 24,297 HE and 1,001,100 ICE Honda and Toyota selected vehicles in 16 States. A total of 186 and 5,699 HE and ICE vehicles respectively were involved in pedestrian crashes. A total of 116 and 3,052 HE and ICE vehicles respectively were involved in bicycle crashes. Overall, the odds ratios indicate that the odds of an HE vehicle being in either a pedestrian or bicycle crash are greater than the odds of an ICE vehicle being in a similar crash with odds ratios of 1.35 and 1.57 respectively, both of which are statistically significant with p-values under 0.01 percent.
The crash factors of speed limit, vehicle maneuver and location were examined to determine the relative incidence rates of HE versus ICE vehicles and whether the odds ratio (OR) was different under different circumstances. While the results did not provide an apparent set of scenarios for bicycle crashes, the findings provide a clearer picture regarding pedestrian crashes. The largest differences between the involvement of HE and ICE vehicles in pedestrian crashes occur with speed limits of 35 mph and lower (OR =1.39), during low-speed maneuvers (OR = 1.66) and when the crash is on the roadway (OR = 1.50). This update further extends the analysis to various other vehicle samples with similar results. For example a comparison of all HE versus ICE passenger vehicles regardless of makes and models indicates that the odds of any HE passenger vehicle being in a pedestrian crash are 22 percent greater than the odds of any ICE passenger vehicle. A comparison of particular pairs of HE and ICE vehicles in pedestrian crashes indicated that under low-speed maneuvers, the odds ratio for the HE Prius versus the ICE Corolla was 1.54, and the odds ratio for the HE Civic versus the ICE Civic was 2.14.
While this study provides useful information about the differences in the incidence rates of HE versus ICE vehicles involved in pedestrian crashes, there are two important limitations to consider. First, the analysis of 16 States cannot be used to directly estimate the national problem size. Secondly, as indicated in an analysis of statistical power, there is not enough data to draw conclusions in all scenarios of interest such as for specific low-speed maneuvers or in parking lots.
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“NHTSA was established by the Highway Safety Act of 1970 to carry out
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Bureau. Specifically, the agency directs the highway safety and consumer
programs established by the National Traffic and Motor Vehicle Safety
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