INNOVATIVE VISIBILITY-BASED MEASURES OF EFFECTIVENESS FOR WIDER LONGITUDINAL PAVEMENT MARKINGS

A 2001 survey of international, U.S., and Canadian transportation agencies confirmed that many are using wider-than-standard longitudinal pavement markings. The survey data shows that most agency personnel believe that increases in line width result in increased visibility of the lines vs. those of narrow widths, ultimately leading to improved highway safety. However, further analysis of the survey data suggests the basis for implementation of wider lines often lies in subjective and qualitative visibility comparisons, including driver surveys and nighttime visual observations made by agency personnel. Measures involving long-range foveal detection of wider vs. standard markings are common in the literature and have shown positive results. However, subjective opinions that wider lines are 'better' may be due in part to increased peripheral visibility and consequently, decreased driver workload. Thus, investigations into line width, as well as brightness, could be improved by use of new measures of effectiveness related to changes in peripheral vision and driver comfort or workload. Such measures could be borrowed from other areas of cognitive science and human performance or based on traditional traffic-related performance measures. These measures are the focus of the research efforts of this paper.