Development of a Crashworthy Pedestrian Rail
Karla Lechtenberg, Jennifer Schmidt, Ronald Faller, Ana Guajardo, Bob Bielenberg, John Reid
The National Highway Traffic Safety Administration (NHTSA) estimated that approximately 4,300 pedestrian fatalities occurred in the United States in 2010. Risk of pedestrian injury is highest when crossing the street. In locations where pedestrians choose a more direct path and cross the street at non-designated crossing areas, driver expectations are violated and perception-reaction times are delayed, thus increasing risk to the pedestrian. Pedestrian rails may be placed adjacent to roadways to protect pedestrians from dangerous excursions into the roadway as well as from hazardous drop offs. Although numerous pedestrian rails have been designed, their performance has never been evaluated during vehicular impact events. Therefore, the Wisconsin Department of Transportation funded a study to develop a crashworthy pedestrian rail system which satisfies the Manual for Assessing Safety Hardware (MASH) TL-2 channelizer evaluation criteria. A total of twenty-five initial pedestrian rail concepts were designed, and four were advanced for final consideration and dynamic bogie testing. An aluminum rail with welded posts, rails, and spindles was selected for full-scale crash testing. The system consisted of 2-in. x 4-in. x ¼-in. x 43-in. tall (51-mm x 102-mm x 6-mm x 1,029-mm tall) posts with three 2-in. x 2-in. x ⅛-in. (51-mm x 51-mm x 3-mm) rail components at heights of 42 in. (1,067 mm), 2415/16 in. (633 mm) and 7⅞ in. (200 mm). Two full-scale crash tests were conducted according to MASH TL-2 test designation no. 2-90, but at impact angles of 25 and 0 degrees for test nos. APR-1 and APR-2, respectively. Both tests successfully satisfied the MASH channelizer evaluation criteria. However, the 0-degree impact showed that the pedestrian rail system was near the maximum ridedown acceleration limit. Thus, further modifications are recommended to improve the crashworthiness of the welded aluminum pedestrian rail design and to lower the occupant risk values.
Highway Safety, Crash Test, Bogie Test, Roadside Appurtenances, Roadside Safety, MASH, AASHTO, ADA, LRFD, Longitudinal Channelizer, Pedestrian Rail, and TL-2