Investigating safety effects of wider longitudinal pavement markings

Many road authorities in Canada have been contemplating the use of wider longitudinal pavement markings (LPMs) to enhance road safety and driver comfort. However, conclusive evidence on the safety impacts of wider LPMs has not been available. To address this gap in the literature, this study was conducted to investigate the safety impacts of wider LPMs. The study adopted the Full Bayes approach to conduct a before and after safety evaluation, using data collected from 38 treatment sites (highway segments) from three Canadian jurisdictions (i.e., British Columbia, Alberta, and Quebec). Collision and traffic data were obtained from the 38 sites over a period of eight years (2008-2015). The widths of LPMs at all sites were increased between 2012 and 2013, which enables a before and after safety evaluation to investigate the impact of the wider markings on the collision frequency. The results showed an overall significant reduction in both total collisions and target collisions (i.e., run-off-the-road collisions) by 12.3 % and 19.0 %, respectively, after implementing the wider LPMs. Total collisions were reduced by 11.1 %, 27.5 %, and 1.1 % in Alberta, British Columbia, and Quebec, respectively. Similarly, a reduction in the run-off-the-road collisions that ranged between 22.7 % and 28.9 % were observed in the three jurisdictions. The results suggest that wider longitudinal pavement markings can reduce collisions and improve safety on Canadian highways. As such, road authorities should consider using this intervention to enhance road safety, particularly, at locations that experience a high frequency of run-off-the-road collisions.