A couple of possible time restrictions come to mind:
- Part of the Bow Valley Parkway in Banff Nat Park has seasonal and dayline restrictions to protect wildlife (i.e. reduce run ins between wildlife and cars).
- many of the small border crossings are closed at night.
However I can't trigger such a warning when I play with routes on Mapquest, though I see such a routing option.
I just found one time restriction - in Vancouver
Turn right onto Oak St/BC-99 S. Continue to follow BC-99 S.
BC-99 S is just past Osler St
Closed to vehicle traffic: Mon-Fri Midnight (start of day) to 5:45 AM
Closed to vehicle traffic: Sat,Sun All day
If you reach Shaughnessy St you've gone a little too far
Another Vancouver restriction:
.
Turn left onto Kootenay St.
Kootenay St is 0.1 miles past Skeena St
Capota's Pizza is on the corner
Timed turn restriction: Mon-Fri 3:00 PM to 6:00 PM
So if there are restrictions, the detailed directions should elaborate.