Road network optimization using heuristic and linear programming

Abstract

To minimize the cost of logging, it is necessary to optimize the road density. The aim of this study was to determine optimal road spacing (ORS) in Northern Austria. The stepwise regression method was used in modelling. The production rate of tower yarder was 10.4 m3/PSHo (Productive system hours) and cost of 19.71 €.m-3. ORS was studied by calculating road construction cost, installation cost and yarding cost per m3 for different road spacing. The minimum total cost occurred at 39.15 €.m-3 and ORS would be 474 m assuming uphill and downhill yarding. The optimal road density and yarding distance are 21.1 m.ha-1 and 90 m, respectively. A sample logging area was used to plan different roads and, using network analysis, the best solution was found based on a modified shortest path algorithm. The network analysis results were very different from the optimal road spacing results that assumed roads and logging corridors could be located anywhere in the planning area at a constant cost. Mixed integer programming was also used to get a real optimal solution.

Keywords

• cable yarding
• mixed integer programming
• network analysis
• optimum road density
• production