Through modeling, actual collisions can be reconstructed and reenacted numerous times at nominal expense. The models can be used for an actual demonstration of the accident in the courtroom, or they may be filmed using multistate stroboscopy or high speed cinematography. When dynamic similarity exists between the models and the full-size vehicles, data measured by using the models may be quantitatively related to the behavior of the prototypes. Such similarity can be obtained if the models are exactly scaled versions of the prototypes and if the 18 physical conditions that affect the dynamics of an accident (such as distances, velocities, angles, weights, and road surface conditions) are satisfied. For the models, a scale of 1 to 25 is recommended because of the enormous number of plastic models available. To prepare the models, the model's original plastic undercarriage is replaced with a brass frame which supports a heavy duty DC (direct current) motor, the drive shaft, and the axles. The model vehicles are weighted so that their weights and centers of gravity are proportional to those of the actual vehicles. Panels from the models' plastic bodies are removed and replaced with either laminated sheets of aluminum foil formed directly over the plastic panels or with light foam plastic cast in the shape of the original panels. Methods of instrumentation and propulsion are described, as is the construction of road models. This approach to accident reconstruction should eliminate many lawsuits, since both plaintiff and defendant can observe a reenactment of a crash. It also should reduce the chances of erroneous judgment. Photographs and an eight-item reference list are included.