Nexus of Human Factor and Road Geometrics on Traffic Accidents along Mzuzu - Jenda M1 Road Stretch

Abstract

In Malawi, approximately 20 road traffic accidents occur every day and about 1000 people are killed every year. Mzuzu-Jenda M1 road is one of the accidents prone stretches. Although the road serves as a back-borne route for inputs and exports to and from neighbouring countries, it has had several fatal accidents. This study was conducted to analyse factors leading to accidents in selected hot spots. Specifically, the study looked at the geometric elements of the road, human behaviour leading to accidents, relationship between road geometric elements and human behaviour and its impact on road accidents and modelling alternative road design alignment on accident-prone sections. The methodology included identifying accident-prone areas, conducting topographic surveys to extract geometric elements of road, conducting in-depth interviews with drivers and passengers, and monitoring the speed of the vehicles on those accident-prone areas. Results show Mapanjira, Chilerawalanda, Kasitu, Champhira and Ruviri are the most accident-prone areas. In these areas, geometric elements of super-elevation, sight stopping distance, horizontal clearance, the radius of the curves, lane and shoulder width are less than what is recommended by road design standards of the American Association of State Highway and Transportation Officials and Southern African Transportation and Communications. The geometric elements have made these spots hazardous for drivers even driving at the recommended speed limit. Further, drivers drive at an average high speed of 78 km/hr representing a 30% increase beyond the recommended speed limit of 50 km/hr. The high speed combined with flaws in the geometric elements of the road makes it more likely for drivers to get involved in traffic accidents. The study recommends to properly construct the road sections following the road design standards in the design manuals and widen the shoulder to provide enough horizontal clearance and cushion the sharpens of the curves.