This paper summarizes the results of a research program, performed by Ultrasystems, Inc. and funded by the National Highway Traffic Safety Administration, to develop and improve methods for characterizing automobile front end structures. Computer simulations of each structure and crash environment were conducted using an existing computer simulation program. Two front end structures, a ramped fixed-force system and a variable stroke velocity-sensitive system, were incorporated into bogey vehicles which were crash-tested into a rigid barrier, a variable rigidity barrier, each other, and production vehicle front structures. These test results provided data by which computer simulation of the crash conditions were verified, providing a high degree of confidence in analytical representation of the structural crash responses. The empirical data were extended to other crash environments using the computer simulation techniques.