“…There have been polynomial time constant-factor approximation algorithms for general metrics [HR85, AG90, BDO06, BTV21]. QPTAS algorithms have been designed for the unit demand CVRP in several metrics: Euclidean [DM15], trees or bounded treewidth and beyond [JS22], planar and bounded-genus graphs with fixed tour capacity [BKS17], and minor-free graphs [CFKL20]. When the tour capacity k is small, the unit demand CVRP admits PTAS algorithms on several metrics: Euclidean [HR85, AKTT97, ACL10], planar graphs [BKS19], graphs of bounded highway dimension [BKS18], bounded genus graphs and bounded treewidth graphs [CFKL20].…”