1960s

It was the Quebec Liberal government of the 1960s that saw the construction of further Autoroutes, with a grid numbering system and the introduction of the blue and red shield. The sign is inspired by the American Interstate sign. This was especially needed in light of the fact that many visitors would be flocking to Montreal by car for Expo 67. Montreal's Autoroute Décarie (A-15) and the Louis-Hippolyte Lafontaine Bridge–Tunnel were constructed for that very reason. The Autoroute des Cantons-de-l'Est (Eastern Townships Autoroute - A-10) opened in 1964, and its continuation, A-55 between Magog and Rock Island, opened in 1967, connecting with Interstate 91. What are now the A-20 (part of the Trans-Canada Highway) and the A-15 to New York (connecting with Interstate 87), originally built in the 1940s, were upgraded to expressway standards. The A-20 also connects with Highway 401 in Ontario. A-40 was extended out to Berthierville, and later to Trois-Rivières in the 1970s. Others include Autoroutes 25, 30 (southern beltway), 31, 35 (eventually connecting to Interstate 89), Autoroute Laurentienne (73), and 640 (an unfinished proposed northern beltway).

1970s

The 1970s also saw the completion of the Pierre Laporte Bridge in Quebec City, connecting the south shore of the Saint Lawrence River to the north. In addition to this, the A-73 was extended to Beauce, the A-20 was extended to Rivière-du-Loup, and the Chomedey Autoroute (A-13), the A-19 and the A-440 were constructed in Laval. Autoroutes were built (two sections of A-440, and A-740) and a few more planned in the Quebec City region, creating a dense web, which led to significant sprawl. In 1976, the Parti Québécois came to power, whose platform mandated an expansion of public transportation over the construction of more Autoroutes. Existing Autoroutes were extended (e.g., the A-40 was extended from Trois-Rivières to Quebec City) but no new Autoroutes were built.

The Autoroute des Laurentides, the Autoroute des Cantons-de-l'Est, the Autoroute de la Rive-Nord (North Shore Autoroute), and the A-13 were toll roads until the mid-1980s, when the toll barriers were removed and the province stopped collecting tolls from vehicles using the Autoroutes. The last toll booth was on the Champlain Bridge (A-10,A-15 and A-20). It was removed in 1990 because the Champlain Bridge is federal property and is thus not subject to provincial tolls.

2000s

In the 2000s, there were several high-profile failures and collapses around some Autoroutes, due to aging and crumbling infrastructure, including the Boulevard du Souvenir overpass collapse, De la Concorde overpass collapse, and most recently the Ville-Marie tunnel collapse. An online poll by Léger Marketing conducted shortly after the Viger tunnel collapse found that 88 percent of Montrealers are "worried" about the state of roads, bridges and tunnels in the city, with more than half of respondents saying they are downright "scared" to drive under an overpass (58 percent), on a bridge (54 per cent), or through a tunnel (53 per cent). McGill University's Saeed Mirza stated that ill-advised design choices and poor-quality concrete were used in the construction rush ahead of Expo '67 and the 1976 Olympics. In particular, the concrete used was permeable with lack of proper drainage, and these allowed chlorides from de-icing salts to corrode the steel reinforcements.^[4]