Very nice post Falko! A quick comment on the performance of PROC OPTNET at 13.1. It looks like it took ~1 hour to find the optimal routing. If you are satisfied with 'near optimal' you can use the tsp relobjgap= option. If you set it to relobjgap=0.01, this will stop when the route found is within 1% of provable optimal. For this data, on my machine, PROC OPTNET will find a 'near optimal' solution in about 35 seconds. It spends the rest of the time closing that gap to find the true optimal. For practical problems (like Santa), 'near optimal' is usually "good enough".