Compromise between Cost Minimization and Efficiency Maximization

The first grid represents road construction costs, ranging from low to high. The selected route is an attempt at minimizing such costs, so it follows a path composed of low cost cells. The second grid represents the level of economic efficiency derived if a road crossed a cell (e.g. population density). The selected road tries to maximize efficiency by servicing as much high efficiency cells as possible. It is worth noting that the low cost route and the high efficiency route follow a different path, which raises the question about which route should be selected? More than often a compromise is sought. The third grid represents such a compromise where the route selected tries to satisfy both criteria, so the path crosses cells that have concomitantly a low cost and a high efficiency.