ABSTRACT
The solution of three simultaneous equations that derive from the physics model is not only difficult, but it is also far from sufficient to reconstruct an accident. There are always measurement or observation uncertainties of some sort, and there are almost always missing data. Of course, these affect the results. As a consequence, in any given crash, there are myriad possible solutions. So the problem is not simply to get results, but to get results that comport with all that is known, which may include physical evidence that is not quantifiable. Certainly the results should reflect a position and velocity at impact that is physically achievable by the vehicle and driver. Fact witness testimony should be taken into account (though not necessarily relied on!). The analysis is set up to allow the reconstructionist to check the results, which include parameters that can be examined for reasonableness. One can then make adjustments in the parameters that are not known with that much certainty, and thereby tune the results so that all reasonableness checks are passed. Some of these will be discussed below.
