Estimates of Car-Following Distances on Three Types of Two-Laned Roads

Abstract

A study was conducted to test the ability of subjects to estimate four different car-following distances on three types of two-laned roads: segmented-lined, solid-lined, or unlined. Car-following distances were underestimated more on segmented-lined roads than on unlined roads and more on unlined roads than on solid-lined roads. This finding indicates that the type of cues offered by roads affect drivers' judgments on those roads. It is proposed that the effect of highway delineations on driver skills be determined so that maximum safety for the driving population can be assured in the design of highways.