Over the period 1959-1977 a network of highways has been established in the Montréal region. Among the agglomerations linked to Montréal by this network, seven can be considered as satellite towns: Saint-Jean-sur-Richelieu, Granby, Saint-Hyacinthe, Sorel, Joliette, Saint-Jérôme and Valleyfield. Almost from the beginning, these new expressways induced major development corporations to construct large suburban shopping centres, thereby modifying to their advantage the shopping habits of the residents of the satellite towns. New consumer practices, stimulated by further development of the highways, have had a negative effect on the growth of retail activity within these cities. Some centres have however experienced improved accessibility following the construction of the expressways. Others, by virtue of their location, have suffered increasing competition from Greater Montréal. Finally this shift in the location of commercial activities had facilitated the development of powerful national retail chains that control an increasing proportion of the retail activities in Canada.