IMPROVING AUTOMATIC GRID CELL BASED ROAD ROUTE LOCATION PROCEDURES

Automatic road route location procedures have emerged since digital elevation models have become available and since computer power has been enabling the solution of large combinatorial problems. The most common approach consists of the following solution procedure: (1) identify all possible road segments, which are physically feasible, and (2) to find the combination of road segments, which minimizes cost. This approach has two shortcomings. First, it assumes road-building cost to be route -- independent. Second, the combination of road segments does not result in a traverse, which fulfills the minimum geometric requirements of the road centerline. The paper aims (1) to refine the road link identification procedure for each grid cell, and (2) to allocate route-dependent road construction costs that consider local slope, geology, cross-section geometry, and pavement structure design. It compares alternative road segment identification procedures and route - dependent construction costs estimation with the standard procedure described above.