The benchmark instances were proposed by:
Morán‐Mirabal, L. F., J. L. González‐Velarde, and Mauricio G. C. Resende. “Randomized heuristics for the family traveling salesperson problem.” International Transactions in Operational Research 21.1 (2014): 41-57,
and are instances from the TSPLIB in which families as well as family visits were generated. The costs were obtained by appliying the usual formula for the TSPLIB intances but the costs are not rounded to the nearest integer.