Browsing by Author "Nicholls, Stephen John"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    The effect of South African provincial road condition on the efficiency of forest product transport
    (Stellenbosch : Stellenbosch University, 2004-03) Nicholls, Stephen John; Pulkki, R. E.; Stellenbosch University. Faculty of AgriScience. Dept. of Forest and Wood Science.
    ENGLISH ABSTRACT: The context of the study is concern over declining provincial road condition due to insufficient government funding of road maintenance. These roads are by their public nature used by a wide variety of commercial and private interests contributing a variety of axle loads. There was no information available on the use of these roads by forest companies and the road conditions. Consequently a survey was conducted to determine condition and length of each segment of provincial road in use by forestry companies and the volume of wood transported over them. In addition data was gathered on other users and their contribution to the volume transported over each section. The questionnaire indicated that the provincial roads are in a poor state. The literature review suggested a significant reduction in total cost of transport can be achieved by maintaining or rebuilding these roads. South African forest companies provide the majority of the heaviest axle loading to these roads and must theretore take responsibility tor damage caused to them. Also a variety of forest companies use the same roads and consequently collaborative studies between companies are needed. A modified Dijkstra's algorithm was used to quantify the effect of the condition of South African provincial roads on the efficiency of the transport ottorest products. The model requires digitised raster road and forest map layers combined with transport vehicle specification as input. The products of the model are optimum routes from all source points to a single exit point or sink, the total volume transported across all road nodes and the total cost to extract all wood from a map section. This output allows managers to identify critical roads tor management attention and make tentative estimates of possible reductions to total cost by altering the road condition. The manager is able to test the sensitivity of the solution to changes in variables and gain a better overall picture of the interactions within the system. The model results, and improved understanding, will provide input to more specific and collaborative studies. South African forest managers can respond to the poor provincial road network by conducting ad hue maintenance to these roads to prevent them becoming completely impassable or to rebuild them to their design state and maintain them at that state. The cost of taking no actions is that these roads would eventually become impassable. The road network model determined that, for the study area, a unilateral decision to rebuild and maintain all roads would result in a net increase in transport costs ofR 2 million/year. When compared to the cost of ad hue road improvements for the same area of R 8 million it is obvious that proper road management is a better option. It was shown that 75% of the reduction in total cost is generated by improving only 31 % of the provincial road surface. Consequently, by improving selected roads (20% of the total provincial road network for the area) it was possible to generate a net cost R 2.9 million lower than if the roads were left as they are. If reductions in operating costs are included the net cost to the forest industry is R 3.1 million/year lower than leaving the roads as they are. In addition to the cost being lower, an improved road network would be in place and the current ad hue spending would be unnecessary. On a larger scale it was estimated that poor provincial road management costs the industry as a whole R 26 million or R 1.52/m3/year. This money can be used to offset the costs of maintaining and upgrading roads. It is therefore concluded that the South African forest industry needs to assess its policy on provincial road management and become more active in the managing of these roads. The tool developed and presented is intended as a prototype decision support tool in developing future policies.