A survey of the state departments of transportation and the Ohio Department of Transportation (ODOT) District traffic engineers was conducted and has provided some insight into the temporary pavement marking practices applied by the highway agencies across the United States. A computerised, animated driver comprehensive study was conducted and the results have shown that the proposed Federal system and the fully restored centre line system generally did a better job in conveying the correct passing/no-passing information than the current ODOT system. However, the study also suggested that the current ODOT system has the potential for improvement when coded temporary pavement markings are used. A subjective evaluation of selected temporary pavement marking systems in the field involving 12 evaluators has indicated that the use of the centre line to convey passing information was more appreciated by the evaluators than the use of traffic signs. Vehicle speed and lateral position measurements in the field were conducted and have indicated that drivers seem to lower their vehicle speeds under poor pavement marking visibility conditions. Driver eye fixation data were collected and it was found that some of the newly designed experimental traffic signs (especially symbolic signs) are requiring an excessive number of eye fixations in order to process the information displayed on these new signs. The eye scanning records were also analysed with regard to driver road eye fixations under night-time driving conditions. It was found that darker pavement markings cause shorter preview distances and preview times. The Ohio University proprietary contrast based pavement marking visibility model CARVE was used to determine the maximum longitudinal distance of resurfaced roadway [maximum gap distance (MGD) under dry, non-glare, low-beam illumination conditions] for which no pavement markings are required. MGD was found to be 38 m. CARVE was also used to determine the maximum tolerable pavement marking obliteration for given pavement marking configurations. The allowable obliteration ranged from 10% to 30% of the retro-reflective area removed. Based upon the results it is recommended to use coded temporary centre lines, implemented with removable, high quality retro-reflective pavement marking tape. (A)
Abstract