A transport corridor has the interrelated dimensions: infrastructure (prioritization, border, cross-border interconnectivity, investment, seaport, mode interface, economic cluster, consolidation, clearing, forwarding, dry port, inland container depot); operational services (shipping, national transit, international transit, cross-border integration, customs and border management, road and rail transport services, interoperability, change of vehicles, air transport, third-party access to the port, storage, clearing, forwarding); institutions and regulations to coordinate corridor activities (corridor management; access rights, transit regime, service contracts). Some estimates suggest that each day saved in shipping time is equivalent to about a percentage reduction in ad valorem tariffs (charged as a percentage of the product price applied to imported goods); the percentage of tariff reduction depends on the specific product. Therefore, the corridor operation should include the total time required to deliver goods from the point of origin to the destination. Any international transport impediments are essentially trade barrriers. Under perfect competition, a quota is equivalent to a tariff: a restriction on the physical volume imported will have essentially the same effect as the application of a certain level of tariff. However, this equivalence does not hold under imperfect competition.