Bookmark and Share

This 2008 photo shows the westbound / southbound Mercier Autoroute (QC 138) en route to the Honore Mercier Bridge. Exits are kilometer-based and numbered beginning at the northern end of the Mercier Bridge; they are not based on the actual kilometer-post of QC 138. (Photo by Douglas Kerr,

CONNECTING THE MERCIER BRIDGE WITH A-20: In March 1961, the Ministère de la Voirie du Québec (MVQ) began work on a C$25 million expansion of the northern half of the bridge over which the province had jurisdiction, including construction of an expressway connection to A-20 (Autoroute des Souvenirs) through LaSalle. The MVQ formalized plans for the Mercier Autoroute--the bridge's northern approach--in July 1962.

The Mercier Autoroute, which replaced local street access to the bridge, was built with four lanes from the bridge north to EXIT 2 (Clement Street / St. Patrick Street) and six lanes from EXIT 2 north to A-20. It had a design speed of 100 km/h (60 MPH), but the actual speed limit on the autoroute is 70 km/h (45 MPH). In addition to serving bridge traffic, the short Autoroute also provides access to an industrial area in LaSalle.

Starting at the bridge, the Mercier Autoroute was built with a partial interchange at EXIT 1 (Airlie Street / Newman Boulevard); the interchange has a northbound-only exit and a southbound-only entrance. The expressway transitions to a depressed section taking it under a railroad right-of-way, then emerges from under Jean-Milot Street to a full-diamond interchange at EXIT 2. Past EXIT 2, the expressway transitions to a elevated section, taking it over the Lachine Canal to its northern terminus at A-20, where there is a "directional-T" interchange.

Construction of the expressway caused some disruption in LaSalle, where 40 homes were condemned to make way for the northbound lanes, and in Ville St. Pierre near the interchange with A-20, where businesses along St. James Street (Rue St.-Jacques) were disrupted even though few were condemned. The Mercier Autoroute was completed in 1966.

Realizing the capacity limitations of a four-lane expressway, and expecting a surge in traffic from the South Shore with the completion of Mirabel Airport, the MVQ proposed a six-lane A-13 (Chomedey Autoroute) extension on new alignment. The new A-13 was to have been built 2.4 kilometers (1.5 miles) west of the current alignment to supplement the Mercier Bridge and its approaches. However, opposition on both sides of the St. Lawrence River killed this plan in 1973.

This 2006 photo shows the eastbound / northbound Mercier Autoroute (QC 138) approaching its terminus at A-20 (Autoroute des Souvenirs). This interchange is not numbered from eastbound QC 138. (Photo by Laura Siggia Anderson.)

PART OF A NEWLY EXTENDED A-13: The A-13 designation should be extended south along the Mercier Autoroute and Mercier Bridge (QC 138) south to Kahnawake, then east along the present route of QC 132 to the stub end of the current A-30, replacing the A-730 now proposed for the stub. Service roads would be built along the present alignment of QC 132 to serve homes and businesses in the Kahnawake Reservation. Although this project could be done with a minimal amount of displacement, it is unlikely this project ever would be undertaken given the history of tensions in the area.

SOURCES: "New Approach for Mercier Bridge" by Don Johnson, The Montreal Gazette (7/31/1962); "St. Pierre Hit With Major Traffic Problem," The Montreal Gazette (11/03/1964); "Dream Highways Soon a Reality," The Montreal Gazette (5/15/1965); "Jetport Link Alternate Proposed," The Montreal Gazette (9/14/1972); Ministere des Transports du Quebec.

  • QC 138 and A-13 shields by Wikipedia.
  • Lightpost photos by Douglas Kerr.


  • QC 138 (Steve Alpert)
  • QC 138 (Félix Mathieu-Bégin)
  • QC 138 (Scott Steeves)



  • QC 138 exit list by

Back to The Roads of Metro Montréal home page.

Site contents © by Eastern Roads. This is not an official site run by a government agency. Recommendations provided on this site are strictly those of the author and contributors, not of any government or corporate entity.