Since the follower’s problem ensures that the demand of customers that are within the coverage radius of one or more facilities is allocated to the most preferred facility, the bilevel mathematical program can be formulated as a single-level program. As in Cánovas et al. (2007) , we consider a single-level reformulation of the problem by replacing the follower’s decision problem with a set of valid inequalities that ensure that whenever a customer is within the coverage radius of more than one facility, customer demand will always be allocated to the most preferred facility.