The M and G instances in this directory with 100-300 clients are due to Bektaş et al. (2011). The L instances of size 500-1200 clients are the modified Li instances due to Vidal et al. (2015), where they are presented for the Clustered VRP (CluVRP). We interpret these instances as Generalized VRPs, and round the node coordinate data to integers (by multiplying the original floating point values by 1000 and truncating to integers). Finally, the instances are all formatted to fit PyVRP's VRPLIB format.

Tolga Bektaş, Güneş Erdoğan, and Stefan Røpke (2011). Formulations and Branch-and-Cut Algorithms for the Generalized Vehicle Routing Problem. Transportation Science, 45(3): 299 - 316. https://doi.org/10.1287/trsc.1100.0352.

Thibaut Vidal, Maria Battarra, Anand Subramanian, and Güneş Erdoğan (2015). Hybrid metaheuristics for the Clustered Vehicle Routing Problem. Computers & Operations Research, 58: 87 - 99. https://doi.org/10.1016/j.cor.2014.10.019.