There are two types of roadtrips: the purposeful roadtrip, and the roadtrip for its own sake. The purposeful roadtrip has been around for as long as there have been roads. But the roadtrip for its own sake is a relatively recent phenomenon. Some link it to the idea of the Grand Tour—a renaissance idea that young men of wealth should, at a certain age, travel throughout the continent, absorbing all of the cultural offerings available. As transit opportunities diversified, class ceased to be such a barrier and touring the continent grew in popularity.
The North American roadtrip his a very different history, as the earliest travel was rarely about cultural enrichment but instead about industry. The development of Route 66 in 1926 combined with the rise of the automobile around the same time cemented the roadtrip as part of American culture. An Oklahoma businessman chose the route number, because he thought it would be easy to remember and had a pleasing sound to the number; the R&B standard—covered by musicians from Nat King Cole to Depeche Mode—has proved him right on that account. The anthem has become the unofficial anthem of the American roadtrip. In recent years, increasingly wide and busy freeways occupy a major role in American travel and transportation, but a true road-trip requires at least some time spent getting off the freeways and enjoying the smaller highways that connect one town to the next, and the song perfectly captures the spirit of this.
The quintessential Canadian roadtrip is the Trans-Canada highway, which wasn't officially completed until 1971. In contrast to Route 66, the unofficial anthem of the Canadian roadtrip is the austere and haunting Northwest Passage by the late Stan Rogers. Rogers focuses on the wilderness and a link between modern travellers and the early explorers of the country; it's about the spaces between the towns, just as Route 66 is as much about the towns themselves, and it helped the relatively new highway become a source of national identity.