Hybrid vehicles have higher pedestrian incidents

A recent report from the National Highway Transportation Safety Administration (NHTSA) has found that hybrid electric vehicles have a higher incidence rate of pedestrian and bicyclist crashes than do conventional vehicles in certain situations.

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.

For more on vehicle safety, see our safety guide and read "Quiet-running hybrids and electrics need audible backup alerts"

—Liza Barth 

Comments

[Fred]

I would imagine pedestrian-rich urban areas have a higher percentage of hybrids - meaning they are exposed to more pedestrians than a typical ICE car. This may explain some of the increase in accidents

[Walter]

Couldn't the statistical difference be explained entirely by the fact that hybrids log more miles in urban areas, where pedestrians are encountered? Hybrids are best in city driving, and perform comparatively poorly on the highway. Accordingly, city drivers buy them more than highway drivers, and those who own both a hybrid and non-hybrid are more likely to drive the hybrid in the city, the non-hybrid on the highway. Pedestrians are in the city, not on the highway. Thus the driving pattern alone could explain why hybrids hit pedestrians more often -- more of the hybrid miles are city miles.

[Eric]

This study is no surprise. The main factor being the noise difference between eclectic and petroleum powered engines. I remember riding in my college buddy's 1980 Toyota Tercel 25 years ago. The engine was so quite on idle, when you came to a stop, you could not hear it and thought the engine had died. I noticed a safety issue just drive through neighborhoods at low speed. You would come up behind pedestrians walking in the middle of the street and have to slow down or even stop. They would not hear the engine until the car was just 20 feet (or less) behind them. They would turn their heads and look behind and be total surprised to see a car so close. This happened in quite neighborhoods. Imagine a even lower noise producing hybrid in a busy intersection with all the background noise.

[Dan]

Anyone that's taken statistics realizes that a difference of .3% is statistically insignificant. It's like coming to the conclusion that red cars are less likely to hit peds and bicyclists than black colored cars because 24 more black cars hit peds out of a total of 8000 cars.

[Bob Wilson]

This report lacks a count of vehicles by type. Counting accidents and dividing by the number of vehicles gives a useful, credible rate. Instead, we have counts of accidents and though we can learn something about relative profiles, these are not a rate per vehicle type or actual risks.

Looking at profiles, there are bulges in one area but as shown in table 3d a dip in the number of 'straight line' accidents for hybrids. Projecting an increase in 3% of the 3,667 hybrid accidents to match the gas car rates would give 110 incidents, more than the number of pedestrian turning and backing accident counts, 19 and 7. One could claim that hybrids save four times the number of pedestrian turning and backing accidents in straight line accidents.

This is the problem looking at just accident counts leads to by emphasizing changes in small numbers without seeing the big picture. We really need accidents by vehicle or vehicle mile.

We studied the Prius accident fatality rate per 100 million miles from 2000-2007 and compared it to the NHTSA annual rate. We found the Prius has half the fatality rate of the USA fleet. This is what we need, accidents per vehicle, and not trying to read something from relative accident counts.