[darth_freeman]

This is actually a fairly good point - I see the 413 creating some major weaving issues on the 401 east of the 404/413 interchange. The 413 will merge with the 401 only a short distance before the 401 splits into the collector / express - I can see a lot of cars weaving over to make it into the 401 express lanes. Not a good design at all.

Ideally the express would run right to the 413 ramps before merging to a single carriageway under the 407 only. Traffic levels on the 401 through the interchange would be substantially lower on either side, as a very large volume of vehicles will be interchanging with the 413 itself.

1. There is more distance between the 413 EB merge and collector/express start than you might think. Plenty of weaving distance room (about 2.5km).
2. Volume from 413WB to 401EB is relatively low as you might expect.
3. As you mentioned, a lot of 401EB traffic will now be going to 413 EB instead, so weaving conflicts are even less of an issue.