How multi-pass dispatch beats greedy nearest-neighbor routing

The simplest way to build a route is greedy nearest-neighbor: start at the depot, go to the closest unvisited stop, repeat. It's fast, it's easy to implement, and it's a trap: every decision is made looking only one stop ahead, so it happily paints itself into corners. The stop it strands for last is often the one furthest from everything else, turning a route that looked efficient for its first 90% into a long, wasteful tail.

A multi-pass approach accepts that dispatch is not one decision but several, made in sequence with different goals: an initial pass clusters stops into truck-sized, window-compatible groups; a second pass sequences each cluster for shortest travel; a later pass sweeps up whatever the earlier passes couldn't place, using idle capacity that only became visible once the rest of the fleet was committed.

The result reads less like "the shortest path a computer could find" and more like what an experienced dispatcher actually does: commit the easy 80% quickly, then spend real attention on the leftover 20% where the constraints actually conflict. That's the part worth automating well. The easy stops were never the problem; the hard stops are exactly where manual planning runs out of time.