Harruff 1998 - “Analysis of Circumstances and Injuries in 217 Pedestrian Traffic Fatalities”

Harruff RC, Avery A, Alter-Pandya AS.
“Analysis of Circumstances and Injuries in 217 Pedestrian Traffic Fatalities”
Accident Analysis and Prevention
January 1998; v.30,n.1; pp.11-20
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Harruff et al analyzed 217 pedestrian fatalities in King County, WA to describe the most common situations and characteristics of pedestrian fatalities.  The average annual pedestrian fatality rate for all pedestrians overstates the risk for responsible, able-bodied adults but understates the risk for vulnerable groups such as the elderly.  Alcohol consumption, disregard of traffic rules, and being male also increase the fatality risk. 

The average annual pedestrian fatality rates for King county for 1990-95 were (per 100,000):

• 2.0 for all ages and both sexes
• 1.0 for the 22-34 year age group
• 1.5 for children under 7 year
• 7.0 for ages 70 years and older

Place of accident: 66% of incidents occurred on city or residential streets, 29% were on main thoroughfares (including highways and freeways; Hwy99 accounted for 12% of all pedestrian fatalities).

Pedestrian activity

• 46% crossing roadway, not in crosswalk
• 21% crossing roadway, in crosswalk
• 5% crossing road way, unknown if in crosswalk
• 14% walking or standing in roadway or shoulder
• 4% away from roadway
• 3% construction zone worker
• 7% miscellaneous activities (attending stalled vehicles, assisting another person or animal)

Alcohol: Of 180 cases with known blood alcohol concentrations (BAC), 24% had some alcohol present (.01-.37 BAC) and 17% had BAC>.10.  Of the pedestrian deaths on Hwy99 tested for alcohol, 47% tested positive with a BAC range of .04-.28.

Older Pedestrians
The authors suggest that older adults may be more vulnerable because 1) the traffic environment (crosswalk controls, impatient drivers) is not meant for slow walkers; 2) they may be less likely to perceive a hazard; 3) they may be less likely react to one even if they do perceive it and to sustain injury from their evasive action; and 4) they are more likely to die of a given injury that a younger person could survive.

Author Notes
The authors question the value of the pedestrian right-of-way law because it may cause pedestrians to be less cautious when crossing the road.  Similarly, pedestrians may also be less cautious in crosswalks.

Surprisingly, the authors also found no significant correlation between vehicle velocity and the extent of pedestrian injuries, suggesting that the way in which the car hits the pedestrian is more important than the speed at which it hits it; however, they admit that their estimate of vehicle speed was imprecise.