Abstract: Hub networks are often designed for efficiency through economies of scale. However, this structure also encourages shipping large volume of freight through a small number of hubs and links. Ignoring congestion and capacity limitations during hub network design can lead to over-consolidation on critical links, resulting in less reliable performance and higher overall cost. This study models the hub network design problem under link capacity and congestion as a mathematical program solved using both heuristic and exact solution methods to examine how these operational considerations affect long-term hub network design and develop planning insights. The analysis shows that network designs that appear cost-effective under idealized assumptions may perform poorly once congestion is considered. Specifically, accounting for congestion can alter both hub locations and inter-hub link selections, leading to more balanced network structures and flow distributions that reduce over-consolidation. This study highlights how strategic network design can support more reliable operations, especially during high-volume periods, and lead to more robust and cost-effective hub networks.