Operations Research

Search and routing problems where the objective is expected time, not distance

Where to Look First

Not the travelling salesman's route — you stop when you find it, so the legs at the end may never be driven

When the Map Is Only a Table

The same search on a graph, where the costs need not be distances and the places need not be equally likely

The Ball That Rolls Downhill

Solving a linear program from the inside, by growing the largest ball that fits and sliding it downhill