Abstract
The safety benefits of raised medians versus depressed medians of interstate highways are discussed. A case study to evaluate wrong-way entry incidents as related to intersection geometry, markings, and signs is presented. Some technologic aspects of the public responsibility related to train detection techniques at rail-highway grade crossings are described. A model to design more efficient urban transportation systems, with special emphasis on the management of parking prices in a way that will minimize total driving and driver walking distances, is reported.