Evaluation of driver visual demand at different traffic volumes on complex two-dimensional multi-lane highway alignments

This research focuses on evaluating driver visual demand at different traffic volumes along with geometric design features for two-dimensional (2D) multi-lane highways consisting of horizontal and vertical alignments which is a crucial part of highway design consistency research. Three such alignments, with simple and complex curves were designed to generate desired traffic volume levels. A driving simulator was used to collect date from twenty drivers that participated in roadway alignment experiments at Ryerson University. Statistical Analysis Software (SAS) was used to analyze and process output data. Models were developed for visual demand and volume/capacity ratios, and geometric characteristics of the road, where visual demand was the only dependent variable. The research found that a relationship exists between visual demand and different traffic volumes along with geometric characteristics of the road.