That's awesome, Moncton.
We only have:
St. John's to Whitbourne: 90km
Corner Brook to Pasadena: 33km
So about 125km of divided highway total. The you add in little portions where the highway is divided through specific communities, such as Grand Falls-Windsor and Port-aux-Basques. You can probably get another 10km or so that way.
So 135km out of the total length of the TCH across the island, which is just over 900km.
There's only one other major highway that's divided, the Conception Bay Bypass, which links downtown St. John's to the suburban town of Conception Bay South. It'll probably have to be widened to six lanes soon, because public transportation isn't an accepted alternative here. It's basically empty all of the time except during the morning/evening rush, when it's often a parking lot.
And there are a couple of divided inner-city highways in St. John's. But those are just pocket change in length, with lots of access points and fairly regular lights, etc.
The only exception is the Outer Ring Road, which is a proper divided highway with no lights, etc. BUT I believe it's part of the TCH. And I've included it in the TCH's total in any event.
But the rest are like this:

Prince Phillip Drive

Columbus Drive at Thorburn Road

Allandale Road at Higgins Line