Coming back from Montreal a couple of times this past month, I was amazed the there are still only 3 lanes in each direction. This started at kilometer 479.
Then traffic joined from Cobourg and Port Hope. Then from 35/115. Then from Bowmanville, Oshawa and Whitby. Finally, the exit to Salem Road at km 405 - still the 3 lanes are just ending.
I realize there is a fair bit of construction going on to widen here - but its surprising they let it get to this state. (although maybe the people in northwest Mississauga - Winston Churchill/401 - could say the same thing).