This study begins by analysing the fatality situation in both Europe and in the United States. The aim was to show where people died, and who died. The resulting experiences revealed: (1) that about 50% or even more of the fatalities can be attributed to two-lane rural highways; and (2) that at least half of them can be attributed to curved roadway sections and the corresponding transitions. Three safety criteria for modern highway geometric design guidelines were developed. The aim was to alleviate the accident risk at the critical locations. The three safety criteria are directed at: (i) achieving consistency in the alignment; (ii) harmonizing design speed and operating speed; and (iii) at providing adequate dynamic operating speed; and (iii) at providing adequate dynamic safety of driving. The three safety criteria were combined into a safety module for evaluating road networks, according to good, fair or poor design. The criteria can be applied either manually or by using a Geographical Information System (GIS). A case study explains how hazardous sections of the "old" alignment can be transferred into an overall sound "curvilinear alignment" representing only "good design levels". This procedure is based on the three safety criteria.
Abstract