Since then, many variants which place restrictions on the shape of the neighbourhoods have been shown to have a PTAS. This includes disjoint fat convex regions [6], pairwise-disjoint connected regions of any shape [16], arbitrary disjoint fat regions [15], and weakly disjoint neighbourhoods ...
Wediscussapplicationsto,andcomputationalexperiencewith,TSPswithtimewindows,amodelfrequentlyusedinvehicleroutingaswellasinschedulingwithsetup,releaseanddeliverytimes.Wealsointroduceanewmodel,theTSPwithtargettimes,applicabletoJust-in-Timeschedulingproblems.FinallyforTSPsthathavenoprecedencerestrictions,weusethealgorithmasaheu...
We then look at several natural restrictions on the scenarios, namely small, big and nested scenarios. We give strong inapproximability results for small scenarios, a constant-factor approximation for big scenarios (where a constant number of vertices is missing per scenario) and a 9-...
step-by-step, further restrictions are added, each involving sums of fractions assigned to roads. Linear programming eventually points us to the best decision for each road, and thus the shortest possible route.