An overview of NHTSA’s crash reconstruction software WinSMASH

wbldb

Sharma, Dinesh¹; Stern, Seymour¹; Brophy, John¹; Choi, Eun-Ha²

An overview of NHTSA’s crash reconstruction software WinSMASH

Proceedings of the 20th International Technical Conference on the Enhanced Safety of Vehicles (ESV)

Affiliations

¹National Highway Traffic Safety Administration, USA

²Rainbow Technology, USA
Abstract

The National Highway Traffic Safety Administration (NHTSA) uses WinSMASH computer software to estimate the change in velocity, delta-V, of the vehicles involved in crashes. The software uses detailed measurements from the crash scene, vehicle damage and vehicle stiffness characteristics to compute energy absorbed by the vehicle and estimate the delta-V and Barrier Equivalent Speed (BES). The WinSMASH is a Microsoft Windows based, enhanced and updated version of the accident reconstruction software CRASH3 previously used by NHTSA. The purpose of this paper is to describe the new enhancements in the program.

The damage algorithm used in CRASH3 has been reformulated in WinSMASH. The new damage algorithm in WinSMASH is based on an assumed linear relationship between crash energy and crush and uses intercept d0 and slope d1 to describe vehicle stiffness. The software uses generic vehicle size and stiffness categories based on the vehicle’s wheelbase. However, the program also allows the users to enter the vehicle specific stiffness coefficients. The stiffness coefficients for a large number of vehicles have been calculated from crash test results and integrated into WinSMASH. An automated procedure to select the vehicle specific stiffness coefficients is currently under development. A statistical model is also being developed for estimating the stiffness coefficients of a vehicle that is not crash tested. The paper provides an overview of these procedures.

The WinSMASH estimated delta-V of the vehicles is compared with the corresponding delta-V obtained from the Event Data Recorder (EDR) installed in the crashed vehicles to assess the accuracy of the software. The staged crash tests used to validate the software are also discussed in the paper.
Links

URL: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv20/07-0211-W.pdf

Cited Works (2)

Year	Entry
2006	Niehoff P, Gabler HC. The accuracy of winsmash delta-v estimates: the influence of vehicle type, stiffness, and impact mode. In: 50th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 16-18, 2006; Chicago, IL.73-89.
2005	Niehoff P, Gabler HC, Brophy J, Chidester C, Hinch J, Ragland C. Evaluation of event data recorders in full systems crash tests. In: Proceedings of the 19th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 6-9, 2005; Washington, DC.

Cited By (27)

Year	Entry
2008	Funk JR, Cormier JM, Gabler HC. Effect of delta-V errors in NASS on frontal crash risk calculations. In: 52nd Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 6-8, 2008; San Diego, CA.155-164.
2009	Hampton CE, Gabler HC. NASS/CDS delta-V estimates: the influence of enhancements to the WinSmash crash reconstruction code. In: 53rd Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 5-7, 2009; Baltimore, MD.91-102.
2010	Hampton CE, Gabler HC. Evaluation of the accuracy of NASS/CDS delta-V estimates from the enhanced winsmash algorithm. In: 54th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 17-20, 2010; Las Vegas, NV.241-251.
2011	Hallman JJ, Yoganandan N, Pintar FA, Maiman DJ. Injury differences between small and large overlap frontal crashes. In: 55th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 3-5, 2011; Paris, France.147-157.
2011	Yoganandan N, Fitzharris M, Pintar FA, Stemper BD, Rinaldi J, Maiman DJ, Fildes BN. Demographics, velocity distributions, and impact type as predictors of AIS 4+ head injuries in motor vehicle crashes. In: 55th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). October 3-5, 2011; Paris, France.267-280.
2007	Wang Q, Gabler HC. Accuracy of vehicle frontal stiffness estimates for crash reconstruction. In: Proceedings of the 20th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 18-21, 2007; Lyon, France.
2009	Craig M, Scarboro M, Flannagan C. Combining CIREN and NASS-CDS data to predict occupant outcomes in frontal crashes. In: Proceedings of the 21st International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 15-18, 2009; Stuttgart, Germany.
2011	Craig MJ, Scarboro M, Ridella SA. Predicting occupant outcomes with EDR data. In: Proceedings of the 22nd International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 13-16, 2011; Washington, DC.
2011	Kusano KD, Gabler HC. Potential effectiveness of integrated forward collision warning, pre-collision brake assist, and automated pre-collision braking systems in real-world, rear-end collisions. In: Proceedings of the 22nd International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 13-16, 2011; Washington, DC.
2011	Johnson N, Gabler HC. Evaluation of WinSmash accuracy in NHTSA side crash test reconstructions. In: Proceedings of the 22nd International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 13-16, 2011; Washington, DC.
2013	Johnson NS, Sharma D. Preliminary evaluation of NASS-CDS side crash delta-V estimates using event data recorders. In: Proceedings of the 23rd International Technical Conference on the Enhanced Safety of Vehicles (ESV). May 27-30, 2013; Seoul, South Korea.
2015	Stitzel J, Weaver A, Schoell S, Barnard R, Talton J, Martin RS, Meredith JW. Occupant transportation decision algorithm: an advanced automatic crash notification algorithm developed and evaluated for motor vehicle crash occupant triage. In: Proceedings of the 24th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 8-11, 2015; Gothenburg, Sweden.
2017	Gabler HC, Sharma D. Accuracy of WinSMASH in rear crashes using event data recorders. In: Proceedings of the 25th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 5-8, 2017; Detroit, MI.
2019	Wu J, Summers S, Ridella S, Lee E, Kang T, Myers J. Occupant injuries related to rollover crashes and ejections from recent crash data. In: Proceedings of the 26th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 10-13, 2019; Eindhoven, Netherlands.
2013	Stadter GW, Yoganandan N, Halloway DE, Pintar FA. Analysis of nearside narrow object impacts with and without shoulder injuries in real‐world crashes. In: Proceedings of the 2013 International IRCOBI Conference on the Biomechanics of Injury. September 11-13, 2013; Gothenburg, Sweden.698-709.
2016	Klinich KD, Flannagan CAC, Hu J, Reed MP. Potential safety effects of low‐mass vehicles with comprehensive crash avoidance technology. In: Proceedings of the 2016 International IRCOBI Conference on the Biomechanics of Injury. September 14-16, 2016; Malaga, Spain.755-764.
2018	Riexinger LE, Gabler HC. A preliminary characterisation of driver manoeuvres in road departure crashes. In: Proceedings of the 2018 International IRCOBI Conference on the Biomechanics of Injury. September 12-14, 2018; Athens, Greece.484-492.
2023	Bangert LG, Collins CJ, Riexinger LE. Do females have a higher risk of suffering distal tibia fractures in frontal car crashes? In: Proceedings of the 2023 International IRCOBI Conference on the Biomechanics of Injury. September 13-165, 2023; Cambridge, United Kingdom.244-253.
2013	Samaha RR, Prasad P, Nix L. Opportunities for injury reduction in US frontal crashes: an overview by structural engagement, vehicle class, and occupant age. Stapp Car Crash J. November 2013;57:41-467.
2011	Schneider LW, Rupp JD, Scarboro M, Pintar F, Arbogast KB, Rudd RW, Sochor MR, Stitzel J, Sherwood C, MacWilliams JB, Halloway D, Ridella S, Eppinger R. BioTab: a new method for analyzing and documenting injury causation in motor-vehicle crashes. Traffic Inj Prev. June 2011;12(3):256-265.
2008	Gabauer DJ. Predicting Occupant Injury With Vehicle-Based Injury Criteria in Roadside Crashes [PhD thesis]. Virginia Polytechnic Institute and State University; June 6, 2008.
2010	Hampton CE. Injury Risk of Road Departure Crashes Using Modeling and Reconstruction Methods [PhD thesis]. Virginia Polytechnic Institute and State University; August 10, 2010.
2011	Johnson N. Assessment of Crash Energy-Based Side Impact Reconstruction Accuracy [Master's thesis]. Virginia Polytechnic Institute and State University; May 3, 2011.
2013	Kusano KD. Methodology for Determining Crash and Injury Reduction from Emerging Crash Prevention Systems in the U.S. [PhD thesis]. Virginia Polytechnic Institute and State University; 2013.
2015	Johnson NS. Serious and Fatal Injury Risk in Road Departure Crashes With Guardrail [PhD thesis]. Virginia Polytechnic Institute and State University; May 6, 2015.
2018	Holmes DA. The Effect of Lane Departure Warning Systems on Cross-Centerline Crashes [Master's thesis]. Virginia Polytechnic Institute and State University; April 16, 2018.
2021	Riexinger LE. Residual Crashes and Injured Occupants With Lane Departure Prevention Systems [PhD thesis]. Virginia Polytechnic Institute and State University; March 22, 2021.