Fukasawa et al. (2006) described an exact algorithm based on the SP model where the variables correspond to the set of q-routes, introduced by Christofides et al. (1981), while the constraints correspond to the set partitioning constraints (8) and (9) and valid inequalities (13), such as rounded capacity inequalities, framed capacity, strengthened comb, multistar, partial multistar, generalized large multistar and hypotour inequalities, all presented in Lysgaard et al. (2004) for formulation F.