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Traditional accident reconstruction analysis methodologies include the study of the crush-energy relationship of vehicles. By analyzing the measured crush from a vehicle involved in a real world accident and comparing it to a test vehicle with a known energy, from a crash test, the real world vehicle's damage energy can be evaluated. In addition, the change-in-velocity (Delta-V) can be calculated. The largest source of publicly available crash tests is from the National Highway Traffic Safety Administration (NHTSA). NHTSA conducts numerous Federal Motor Vehicle Safety Standard (FMVSS) compliance and New Car Assessment Program (NCAP) testing for many passenger vehicles for sale in the United States.

This paper presents a methodology to determine the approximate closing speed of a striking vehicle and resultant delta-v of the struck vehicle in low speed collinear rear impacts through analysis of the paint damage pattern evident on the struck vehicle's rear bumper. This methodology is only applicable to collisions between vehicles that possess painted flexible plastic foam supported bumpers. Five impacts at each of 1.12 m/s, 1.79 m/s, and 2.69 m/s target speeds and three impacts at 3.58 m/s target speeds were conducted to provide the foundation for this methodology. The use of powdered guidecoat is introduced to contrast the damage pattern on the bumper of the struck vehicle. A measurement of contact paint damage area is obtained and that damage area is then correlated to a closing velocity between the two vehicles. Measured coefficients of restitution and calculated quantities of energy absorbed are also presented for each impact.