Incorporating road safety Into rural road network pavement management

Abstract

Rural roads play an essential part in a country’s road network providing connectivity between the rural communities and the national roads. However, most of these roads are not maintained efficiently and safety issues are often not prioritised since pavement conditions are prioritised, especially in developing countries. Lack of reliable crash data, road condition monitoring regime are often cited as reasons. This study proposes a methodology to incorporate road safety performance in rural roads in maintenance planning using a multi-objective optimisation approach. Road safety performance is defined in terms of the Cumulative Safety Index (CSI), computed based on the severity, exposure, frequency of safety issues, identified in road safety audits. Safety performance and pavement condition-related indices such as International Roughness Index (IRI), pothole number, are included in the optimisation analysis. It comprises two objectives: minimise network IRI, and minimise network CSI. Applicability of the developed model has been demonstrated from the illustrative example of a rural road network. Results shows that roads with safety issues can also be prioritised in budget allocation while ensuring the network level pavement condition can be maintained at a reasonable level. This methodology offers a simplified approach to incorporate road safety issues in rural road PMS.