Performance of Roads Implemented under the Roads 2000 Strategy in Central Kenya

Abstract

The road sector in Kenya is an integral part of its economy. The country has approximately 170,000 kilometres of road network, managed by the line ministry through the Kenya Roads Board (KRB), Road Authorities, and other Agencies. Insufficient financial resources and organisational and operational systems with inadequate investment in maintenance have led to the devaluation of the road network as an asset, as well as the aftermath effects of high vehicle operating costs which directly affect the economy negatively. The deplorable condition of these road assets led the Government of Kenya to shift its emphasis from the construction of new roads to the rehabilitation and maintenance of the existing road network using the maintenance strategy known as the Roads 2000 Strategy. The strategy aims to improve road maintenance and construction by introducing appropriate technology on a road network basis for the selective rehabilitation, spot improvement and maintenance of prioritised links. The strategic goal of the R2000 program is to bring the rural road network of Class D, E, and special purpose roads including parts of the unclassified network to a maintainable standard and ensure that KRB Road Maintenance Levy Fund (RMLF) resources are used to maintain the maintainable and recently improved road network. This study aimed to assess the success and impacts of the R2000 program in Central Kenya. Roads constructed under the three batches of phase two were investigated to establish the current condition of the roads. The present serviceability was assessed and compared to the design life of the roads. The condition survey investigated the traffic status, surface and structural conditions. All the data from these studies were analysed using the appropriate methods and the results were used to make a valid conclusion on the performance of the completed low-volume sealed roads. The major defects on the roads were noted and examined closely to determine the extent and cause of the defects. Such defects included pothole formation, delamination of pavement layers, longitudinal, transverse and crocodile cracking, encroachment of vegetation onto the carriageway and stone loss. Each road had its own specific dominating defects, arising from different prevailing weather, traffic or material conditions and road use. Tests and measurements conducted on the pavements showed the completed low-volume sealed roads generally have a strong pavement that is adequate to carry 15-year design traffic. Axle load surveys showed the 10 and 15-year design traffic classes for completed roads still fall within the expected low-volume sealed roads traffic classes. The roads surveyed generally had good to very good side drainage. The defects observed in the majority of the roads such as cracks, aggregate loss, edge breaks, rutting and potholes, among others, were only limited to the surfacing