Vehicle impact testing, having its start over 30 years ago, has matured into a highly sophisticated operation which involves many disciplines. The older routines of running cars into things and only looking at aftereffects are no longer adequate to answer today's vehicle safety questions. Full-scale testing has been supplemented with impact sleds, component impact machines, and computer simulations. Human simulators, or dummies, are used as instrument carriers or as instruments themselves to provide some estimate of the injury that might be produced in various impact situations.All types of impact tests today demand complete, accurate, and immediate measurements of the physical events involved. Instrumentation has evolved which utilizes electronic, photographic, and mechanical techniques to record and display impact events which, by their very nature, are over in tenths of seconds. Data reduction systems have been devised to shorten the time and reduce the man-hours necessary to make the data useful.Currently, the major limitations in vehicle impact testing appear to lie in the area of incomplete human biomechanical information. How to produce the impact is farther along than knowing what bodyform to impact against or impact with. How to obtain and record the data is less of a problem than how to interpret the results for injury potential.This paper presents a review of vehicle impact testing as it has evolved in the United States by discussing its history, its various forms, the measurements it requires, and the kinds of information it tries to provide.