Sponsored by ANB45 Occupant Protection Committee ANB45 (1) Rollover Crashworthiness Subcommittee Co-Chairs: Raphael Grzebieta & Ken Digges Other sponsors:

First meeting: July 2010

Members/Friends Australia 12 Canada2 France1 Korea3 UK3 Sweden2 USA58 Total 82

MEETING MINUTES ANB45(1) Subcommittee on Rollover Crashworthiness TRB 2013 Mid-Year Meeting: July 15, 2013 TRB Keck Center, Washington D.C.

MEETING MINUTES ANB45(1) Subcommittee on Rollover Crashworthiness TRB 2013 Mid-Year Meeting: July 15, 2013 TRB Keck Center, Washington D.C. Presentations were made by Prof. Ken Digges and Dr. Demet Ozkan and Ms Randa Samaha from the National Crash Analysis Centre (NCAC) George Washington University, and Prof. Raphael Grzebieta from Transport and Road Safety (TARS) Research from the University of New South Wales. The presentation by Prof. Digges was on the Recent Trends in Rollover Crashes and Overview of Involvement with Highway Features was presented. Dr. Ana Maria Eigen from US Federal Highway Safety Administration (FHWA), which was the sponsoring agency for this research project, introduced the presentation given by Prof. Digges. The research objective was to identify potential effects of vehicle changes on rollover and impacts with hardware.

MEETING MINUTES ANB45(1) Subcommittee on Rollover Crashworthiness TRB 2013 Mid-Year Meeting: July 15, 2013 TRB Keck Center, Washington D.C. Prof. Digges analysis of rollover crashes indicated that: Pickup trucks and SUV’s accounted for 49% of all rollover crashes, while VAN’s accounted for only 5%; Pick-up trucks and SUV’s accounted for 46% of rollover crashes where SUV’s were more prone to rollover than pickup trucks. Analysis of rollover crashes by vehicle categories indicated that: SUV’s and pickup trucks have a larger chance to rollover than passenger cars and vans; considerable improvement for SUV’s, with a 50% reduction at the end of the considered period; no improvement for all the other vehicle classes. Analysis of rollover 1st-harmful events indicated that: three major rollover causes are Culvert/ditches, Pole/Trees, and Embankments (for vehicles: Embankments, Culvert/ditches, and Curbs); Three features with highest percentage to cause serious rollover injuries are: Pole/Trees, Guardrails, and Bridges (for vehicles: Guardrails, Narrow Objects, and Culvert/ditches).

MEETING MINUTES ANB45(1) Subcommittee on Rollover Crashworthiness TRB 2013 Mid-Year Meeting: July 15, 2013 TRB Keck Center, Washington D.C. Analysis of vehicle model year indicated that: vehicles before 1990 are almost twice as likely to rollover than vehicles; Model year have 20% higher injury rate in rollover than vehicles; SUV’s manufactured on or after 2005 have a rollover involvement similar to cars; and Model year pickup trucks have a higher rollover rate Curb/Guradrail/Narrow Objects rollover rate than SUV’s. Dr Ozkan discussed the Pre-Crash factors that Influence Single Vehicle Rollovers in the USA. He found that: about 82% of rollovers are single-vehicle crashes; there was negligible reduction in single-vehicle crashes over 12 years; analysis of vehicle model year indicated that odds of rollover for SUV’s are 2.5 more than SUV’s, odds of rollover for SUV’s are similar to cars, and odds of rollover for pickup trucks are 2 times more than cars. He also found that Roadway profile (Horizontal and Vertical alignment): 40% of all single-vehicle rollovers occurred on slopes (odds of rollover on slope twice as on flat terrain); SUV’s have improved on flat terrain, but not on slopes; and 30% of all single-vehicle rollovers occurred on curves (odds 2.3 times more than on a straight road).

MEETING MINUTES ANB45(1) Subcommittee on Rollover Crashworthiness TRB 2013 Mid-Year Meeting: July 15, 2013 TRB Keck Center, Washington D.C. Ms Samaha investigated critical variables and associated trends for rollovers involved with embankments using NASS crash data (period ). She found that Almost 40% of rollovers started from front-right of the vehicle; The majority of rollovers on off- road surface occurred on dirt/grass; and about 80% of crashes occurred w/ vehicle travelling uphill. Prof. Grzebieta summarised the research regarding the UNSW Jordan Rollover System (JRS) to test vehicle rollover in a lab environment. Initial issue due to excessive friction between the roadbed and the underneath sliding supports were solved using supports with rollers rather than simple frictional supports. Preliminary computer simulations showed it was possibile to accurately simulate both the vehicle kinematics and deformation during the entire duration of the test with a JRS rig.