Since the point of signing a trade agreement is to improve economic growth, it is usually the case that the countries invest in infrastructure to support higher volumes of freight movement. Consistent data on U.S. public sector infrastructure investment over a long-term horizon is not readily available, but existing data indicates that this has generally not kept pace with economic or population growth. Railroads have continued to invest a large amount of their earnings back into their networks. Ports continue to upgrade freight-handling equipment, strengthen quay walls and dredge berths. However, highways, particularly around major port gateways, have not kept pace with freight volume growth, judging by the incidence of congestion.
It is possible that the weak spending on infrastructure helped imports, but was not enough to help exports