Human factors in highway geometric design

Research of human factors in highway engineering may be seen to include two main areas: the effect of geometric design on driver behavior, and the consideration of driver behavior variability. A critical review of pertinent research and related provisions ill the design guidelines of the United States, Germany, and Great Britain is carried out in this paper, and shows that, although a variety of highway-design assessment methods with respect to the aforementioned research areas have been suggested in literature, the relevant findings have not yet been satisfactorily incorporated into highway design guidelines. On the basis of the aforementioned research findings and existing guidelines' provisions, a framework is discussed that allows for the consideration of ''nondesign'' road users, such as older drivers, and also incorporates checks for the overall safety of design as a feedback loop in the design process.