The way it's currently configured, there are too many successive merges between cars heading in different directions on Highways 15 and 40, the province says. Designed in the 1950s, it's used by 280,000 vehicles daily and is the scene of a large number of accidents - 1,637 between 2003 and 2007 alone, Transport Quebec says.
The new interchange, expected to be completed in 2013, is supposed to change that.
In addition, connections to the borough of St. Laurent will be improved and reserved bus lanes will be added.
Here's a computer generated video of the new decarie proposal: