2019 - South Africa - Optimum Unsealed Road Sealing Policy

Road surfacing policy is among the most influential mechanisms available to road authorities to alleviate budget and resource constraints and to enhance their level of public service delivery. Given that gravel roads constitute 73.6% of the South African road network, this paper identifies cost-effective surface solutions for these roads under different local conditions experienced across South Africa. Gravel and cape seals, which are selected as a potential light bituminous seal alternative to gravel, are explored using a Cobb-Douglas production function that represents their major inputs: capital; labour; basic materials; fuel; and other inputs. The respective factor intensities for the production functions are based on 2018 road construction and maintenance unit cost data for South Africa. The relative costeffectiveness of the alternative road surfaces is evaluated through a lifecycle cost analysis (LCCA), with the production function parameters stress tested according to cost variances caused by actual environmental and market conditions. Road user and road accident costs are added as additional LCCA stress tests to extend the study beyond road authority costs. The results indicate that the dominant strategy, in terms of cost-effectiveness and welfare, is for South African road authorities to seal those gravel roads worth maintaining at a rate possible within budget limitations.