Abstract:
Road traffic crashes are one of the major causes of death and injury worldwide, with estimates showing that over 1.3 million road users die every year globally on the world’s roads, and approximately 30 times as many sustain non-fatal injuries. The road traffic crashes burden is felt disproportionately more in developing countries, where road and traffic conditions differ significantly from developed countries. Road user perceptions are influenced by roadway features and play a vital role in determining the crash risk levels on the roads. This study investigated roadway features on surfaced roads with gravel shoulders that play a prominent role in influencing the occurrence of road traffic crashes on rural roads on the Namibian national road network.
The compliance of the physical road features with typical road design standards was determined against those set by the Technical Recommendations for Highways 17 on the Geometric Design of Rural Roads (TRH 17) used in Namibia for some time. The compliance assessment found that road shoulder and lane widths on the studied road sections did not comply with TRH17. The study also developed multivariate road crash prediction models (CPMs) to investigate the statistical significance of the link between road crash incidence and selected road features.
The CPMs identified several interactive relationships between road section lengths, lane widths, shoulder widths, 85th percentile speeds and horizontal curve radii that significantly influence the occurrence of road crashes on the road section. By extension, the CPMs developed will assist transportation safety authorities in identifying road features influencing crash incidence and implementing appropriate road safety measures with the intent to promote a safer road system.
