3 ms·

Undefined start or end time with a limit on driving duration is not trivial. Well, routing school buses is already less than trivial. You have pickup & deliver

Undefined start or end time with a limit on driving duration is not trivial. Well, routing school buses is already less than trivial. You have pickup & delivery. So there's a precedence constraint to orders. Child won't be kept for hours in the bus, so the bus has to make several trips to school. Limiting the time between delivery of the child and the pickup is already less than trivial. Just to know if route is feasible (all constraints satisfied) given a list of child pickups, child dropoffs and time limit between pickup and dropoff is nontrivial and can mess up the optimization. Adding school shifts to the equation, minimizing number of vehicles and a bunch of other constraints might make the optimization just too slow or too constrained for an algorithm that was working incredible without all those constraints.

JoeAltmaier 7y ago
In rural Iowa (where I live and grew up) the middle-school bus and high-school bus are full the first couple of days of school, then they all start driving/getting rides to school. At the middle of the school year, maybe 12 people on a bus build for 60. That makes it complicated too. And 'optimization' solutions result in 1hour+ rides to a school just down the road, as the bus winds about the countryside scavenging the few remaining students. The longer the trip gets, the more that find another way, the emptier the bus, the longer the trip to try to fill it again. We drove our kids to school for most of their school careers, even though three busses went by our house every day.