Driving from Montreal to Quebec City - Canada on Autoroute 20

Autoroute 20 is a Quebec Autoroute, following the Saint Lawrence River through one of the more densely populated parts of Canada, with its central section forming the main route of the Trans-Canada Highway from the A-25 interchange to the A-85 interchange. At 585 km (363.5 mi), it is the longest Autoroute in Quebec. It is one of two main links between Montreal and Quebec City; the other is the A-40.

There are two sections of the A-20, separated by a 57 km (35.4 mi) gap. The mainline extends for 540 km (335.5 mi) from the Ontario border to its current terminus at Trois-Pistoles. The second, more northerly section is far shorter (44 km (27.3 mi)). Constructed as a super two autoroute (one lane in each direction), this section of the A-20 bypasses Rimouski to the south and ends at a roundabout junction with Highway 132 in Mont-Joli. While the Quebec government has completed environmental and economic reviews of the impact of linking the two sections of Autoroute 20, it has not committed the funds necessary for construction. Citing the high number of accidents on the Rimouski-Mont-Joli link of the A-20, many politicians in the Bas-Saint-Laurent region have criticized the government's lack of progress in linking the two sections of autoroute and twinning the two-lane portion.