In this week's viz, we're sharing the latest travel data that has just been published this week by Statistics Canada, running back to 1972 on a monthly basis. We've decided to focus on Canadians making overnight trips to the US, as these trips represent 91% of all overnight trips Canadians make abroad.

Since 1972, Canadians have averaged 3.73 million overnight trips to the US each month, with the latest data (for June 2015), slightly exceeding this, at 3.84 million. As averages are wont to do, this singular statistic masks an enormous amount of variation in the data. For example, February 1992 saw more Canadians overnight in the US than any other month for which data have been recorded (7.13 million people), while the lowest Canada-to-US travel month was May 1974 (only 2.36 million people).

Since the early-1990s the pattern in Canadians' overnight-tripping to the US has largely followed trends in the Canadian-US dollar exchange rate, with rises in the exchange rate (indicating a cheaper US dollar) coinciding with increasing travel volumes; similarly, declines in the exchange rate--as seen through the 1990s and then again more recently--have been accompanied by falling travel volumes. Interesting, this relationship doesn't appear to hold during the pre-1990 period.

Of course, changes in the exchange rate don't, on their own, explain all the movement in travel volumes, with overnight travel from Canada to the US falling by 23 percent in the month following the September 11th attacks in New York and Washington (to 2.50 million trips in October 2001), and travel spiking--to 7.13 million trips in February 1992--not long after the introduction of GST in Canada.