Source: Panama Canal Authority.
The construction of the Panama Canal in the early 20th century was mainly justified to support and expand trade between the US East and West coasts. In 2015, the Panama Canal handled 229.2 million tons of cargo, but American intercoastal trade accounted for less than 1% of this tonnage. The most significant trade route serviced by the canal involves connecting the US East Coast to Asia (35.8%), followed by the West Coast South America / US East Coast route (15.9%). Particularly, the importance of the Asia / East Coast route mostly justified the Panama Canal expansion project to reinforce its economies of scale. However, this route, even if still dominant, does not indicate significant growth prospects as its tonnage declined since 2012. The US East Coast has become a particularly contestable market for containerized trade with Asia. The US East Coast / WCSA and the US East Coast / WCCA routes have grown the most between 2012 and 2015, underlining the growing regional importance of the canal. Economic development in Latin America is expected to increase the amount of intercoastal trade within the region. In more than a century since its opening, the commercial function of the Panama Canal has considerably changed and it is expected that it will continue to do so in the post-expansion era.