ABSTRACT
ABSTRACT: The safety of a road is closely linked to variations in the speed of vehicles traveling on that road. Horizontal and vertical alignments of a highway are designed based on an assumed design speed. Later researchers recognized that drivers select a speed influenced by the roadway condition rather than an assumed design speed. This work attempts to develop operating speed models for crest vertical curves on two-lane non-urban roads in India. Traffic data, crash data for six years and geometric details of 55 sites formed the database for the study. Scatter plot and correlation analyses were carried to identify the candidate variables for developing the models to predict operating speed. Multiple linear regression models were developed. The models developed in the study can be used for the evaluation of the design of vertical curves and establishing speed limits on non-urban roads.
