  We evaluate the robustness of agents' traffic equilibria in randomized
routing games characterized by an uncertain network demand with a possibly
unknown probability distribution. Specifically, we extend the so-called hose
model by considering a traffic equilibrium model where the uncertain network
demand configuration belongs to a polyhedral set, whose shape is itself
a-priori unknown. By exploiting available data, we apply the scenario approach
theory to establish distribution-free feasibility guarantees for agents'
traffic equilibria of the uncertain routing game without the need to know an
explicit characterization of such set. A numerical example on a traffic network
testbed corroborates the proposed theoretical results.
