The Capacitated Vehicle Routing Problem (CVRP) is a combinatorial optimization challenge where vehicles with limited capacity must deliver goods from a central depot to multiple customer locations, minimizing total travel distance while respecting vehicle capacity constraints. 
We use Ant Colony Optimization (ACO) to solve this problem, where artificial ants probabilistically construct routes guided by pheromone trails and heuristic information. 
Your task is to evolve a `heuristics` function that generates a heuristic matrix to guide ant movement, with the goal of minimizing the total distance traveled across all vehicle routes (called "score" or "objective" of solution).