Principal findings of this study were that geometrics alone account for only a small portion of the variance in accidents and that no relationship could be established between fatalities and the geometrics studied. The geometrics studied include several types of interchanges, paved shoulders, sight distance, delineators, surface types, and other variables. Mathematical models were developed which can provide estimates of the average number of accidents on a particular type of highway or interchange, using the appropriate variables.

Principal findings of this study were that geometrics alone account for only a small portion of the variance in accidents and that no relationship could be established between fatalities and the geometrics studied. The geometrics studied include several types of interchanges, paved shoulders, sight distance, delineators, surface types, and other variables. Mathematical models were developed which can provide estimates of the average number of accidents on a particular type of highway or interchange, using the appropriate variables.

Describes freeway conditions which are subject to improvement by means of electronic surveillance and control. Ramp metering is presented along with a benefit-cost analysis of its effectiveness.