Analysing Runoff Road Crashes

A RUNOFF ROAD CRASH TYP­I­CALLY IN­VOLVES A SIN­GLE VE­HI­CLE LEAV­ING THE IN­TENDED TRAVEL PATH. IN MOST CASES, THE ER­RANT VE­HI­CLE MAY EN­CROACH ONTO THE ROAD­SIDE AND COL­LIDE WITH ROAD­SIDE FUR­NI­TURE AP­PA­RA­TUS DUR­ING THIS DE­PAR­TURE PROCESS.

Insurance - - CONTENTS - Text Ab­dul Rahmat Ab­dul Manap | crashengi­neer­ing@gmail.com

Arunoff road crash is gen­er­ally categorised into two groups: off-road crashes and on-road crashes where the ve­hi­cle re­mained on road af­ter the crash. In analysing runoff road crashes, there are few im­por­tant is­sues that need to be con­sid­ered. First and fore­most is phys­i­cal ev­i­dence per­tain­ing to road mark­ing ev­i­dence com­monly as­so­ci­ated with runoff road crashes. In a clas­sic ‘fish-hook’ crash, where the driver ex­erts ex­ces­sive steer­ing in­put dur­ing a crash avoid­ance ma­noeu­vre, ev­i­dence of a yaw mark is ex­pected on the crash site. A yaw mark is dif­fer­ent from a reg­u­lar brak­ing mark. A yaw mark is a scuff-mark made on a sur­face by a ro­tat­ing tire, which is slip­ping par­al­lel to its axis. A yaw mark is typ­i­cally less per­cep­ti­ble to de­tect, less dense than a nor­mal brak­ing mark and rel­a­tively does not last long. Yet, it is one of the im­por­tant ev­i­dences in analysing a runoff road crash. It not only helps the crash in­ves­ti­ga­tor re­solve some of tech­ni­cal is­sues, such as crit­i­cal speed of the ve­hi­cle be­fore crash or any pos­si­bil­ity of road de­fect and de­sign, it also helps ex­plain driver be­hav­iour be­fore the crash takes place. For in­stance, ex­am­in­ing the exit an­gle of tire marks leav­ing the road­way in a runoff road crash may re­veal driv­ing per­for­mance be­fore the crash. An abrupt exit an­gle of the tire mark may in­di­cate a sud­den ma­noeu­vre in avoid­ance of an ob­sta­cle on the road, while a shal­low exit an­gle (yet an un­usu­ally long tire mark) may im­ply the driver fell asleep a few sec­onds be­fore the crash. The sec­ond is­sue is phys­i­cal ev­i­dence per­tain­ing to the sever­ity of the in­jury from the crash. One of the leading fac­tors that in­crease the in­jury sever­ity in runoff road crashes is that it usu­ally in­volves strik­ing a road­side ob­ject. The col­li­sion is ex­tremely haz­ardous, as these usu­ally in­volve nar­row im­pact and non-ab­sorb­ing en­ergy struc­tures. Specif­i­cally, this type of col­li­sion is char­ac­terised by lack of stop­ping dis­tance, mas­sive de­cel­er­a­tion of force ex­pe­ri­enced by the vic­tim and in­tru­sion of a road­side ob­ject in­side the pas­sen­ger com­part­ment. The most com­monly struck road­side ob­jects are a nat­u­ral or planted tree, a guardrail, poles, bridge para­pets and con­crete bar­ri­ers. It is also worth men­tion­ing that some

Newspapers in English

Newspapers from Malaysia

© PressReader. All rights reserved.