The safety benefit of wide centerline treatments utilizing audio-tactile line-marking on undivided highways

The safety benefit of wide centerline treatments utilizing audio-tactile line-marking on undivided highways

Major highways in Australia cover large distances through rural areas. They are typically undivided, have high operating speeds and carry high traffic volumes. Head-on and crossover-the-centreline crashes are of the most severe crash types that occur on these roads. They are disproportionally represented in crashes resulting in fatalities, yet conventional road design provides no separation between opposing traffic lanes. The Bruce Highway in Queensland, Australia has consistently rated as one of Australia's worst performing roads and is considered a 'killer highway' by the wider community, thus the road authority trialled a Wide Centreline Treatment (WCLT) utilising Audio-Tactile Line-Marking (ATLM). This innovative road safety treatment aims to reduce the incidence of cross centreline crashes by increasing separation between opposing vehicles and providing auditory and vibratory warning to drivers that have strayed from their lane. This paper quantifies the safety benefit following installation of a WCLT on a 56 km segment of the Bruce Highway. An Empirical Bayes analysis was used to account for the regression to the mean bias due to the short period of before and after data available and the higher than normal crash history experienced at the site. Results revealed a significant reduction for all crash types analysed. Importantly head-on crashes were reduced by 75% and both run-off-road-left and total crashes were each reduced by 59%. Further, it shows that the WCLT provides a cost effective safety benefit from its low cost of installation and maintenance. These preliminary yet encouraging results lay the foundation for future consideration and implementation of WCLT's as a road safety initiative for rural highways.