Contained within the 3rd Edition (1957) of the Atlas of Canada is a map that shows the flow of air passenger traffic for major companies circa 1953. Where more than one company operates over the same route, the traffic has been combined to show the total traffic over that route. It should also be noted that the flow lines on this map do not necessarily follow actual routes and they should, therefore, be considered as diagrammatic only. The second map shows the labour force engaged in transportation and communication according to the 1951 Census. The data on which this map is based includes all persons, regardless of their occupation, who were employed in the operations of air transport and airports; bus and coach transportation; railways (including express and telegraph services); taxi cabs; truck and water transportation; and services incidental to all forms of transportation, grain elevators, storage and warehouse facilities, radio broadcasting and telephone services.