This pre-clearance capability, which dates from the early 1950s, reflects a broader tradition of political and economic cooperation that has characterized Canada-U.S. relations since the 19th century. But in recent years, cross-border air travel has increased significantly. Between 2012 and 2018, passenger volumes between Toronto Pearson and U.S. cities grew by 32 per cent, compared to a 26 per cent increase on routes within Canada.
There are many factors behind this continuing growth, including more economical airfares (despite the relative weakening of the Canadian dollar). But a significant driver is the further integration of economic links between the two countries. Notable trends north of the border include expansion into U.S. markets by Canadian banks and other large companies; increased exports of services such as engineering and management consulting; and higher levels of cross-border shopping via e-commerce providers like Amazon.