Pedestrians on the Interstate Highway System present a distinctive traffic safety problem and account for 10 percent of all pedestrian fatalities each year in the United States. Very little research, however, has been conducted to date to investigate the problem of or address pedestrians who are struck by motor vehicles on an Interstate highway. The objective of this report is to quantify and describe pedestrian fatalities on Interstates from 1993 through 2012 at the national and state levels. Pedestrians may enter the Interstate intentionally, often despite restrictions and controls, while drivers and motor vehicle occupants may become “unintended” pedestrians when their vehicle is disabled by a crash or other incident. Both are extremely vulnerable due to lack of pedestrian facilities and exposure to high-speed traffic. Speed limits on the Interstate range from 55 to 85 miles per hour. A pedestrian struck by a vehicle at the low end of this range has an average risk of death of 90 percent, and the risk further increases with speed. Research comparing states has confirmed that an increase in Interstate lane miles is associated with an increase in the number of pedestrians fatally injured on the Interstate. The proportion of pedestrian fatalities occurring on the Interstate in a given state, as well as pedestrian Interstate fatality crash rates, may reflect factors such as the availability and accessibility of the state’s Interstate route(s) to pedestrian use, pedestrian exposure (both on and off the Interstate) which reflects the population, pedestrian risk, overall traffic risk, and ratios of lane miles and vehicle-miles of travel (VMT) on roadways of various types. Countermeasures designed to safely accommodate pedestrians walking along as well as crossing roadways, including many of those codified in the Federal Highway Administration’s Pedestrian Safety Guide and Countermeasure Selection System, are not generally applicable to the Interstate highway environment. The Interstate is generally closed to pedestrians, making countermeasures like roadway and crossing design improvements, specialized enforcement, or traffic calming impractical. Limited countermeasures have been used by states to keep pedestrians off the Interstate and to aid unintended pedestrians, as well as to warn drivers, although the effectiveness of these countermeasures has not been evaluated. Data from the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System (FARS) were obtained for the years 1993 — 2012. This database contains data on all motor vehicle crashes on public roadways in the U.S. that result in a death within 30 days of the event. All fatally injured pedestrians were identified using person type (pedestrian=5) and injury severity (fatal injury=4) as coded in FARS. Bicyclists, other cyclists, and pedestrians on personal conveyances were excluded. Interstate status was determined by using NHTSA’s Roadway Function Class Convention (rural principal arterial — interstate=1 and urban principal arterial — interstate=11). The numbers of pedestrian Interstate fatalities, total pedestrian fatalities, and total fatal Interstate crashes were tabulated by year and state. Annual VMT data by state was downloaded from the Federal Highway Administration’s website. Exposure data for pedestrians on Interstates was not available. The proportion of all pedestrian fatalities that occur on Interstates, the rate per Interstate fatal crashes, and the rate per Interstate VMT were also calculated by year and by state. Crash and pedestrian level characteristics were also explored. Proportions of drivers and pedestrians with positive and illegal blood alcohol concentration (BAC) were computed using NHTSA’s multiply imputed data for individuals whose BAC was missing. (Author/publisher)
Samenvatting