I've done it a few times, both at night and during the day. It's a decent road, and many cyclists use it. Lots of traffic, but what else is new?
I think cars/trucks are used to seeing bikes on it, so I wouldn't worry too much.
The only bad part about it is the climb up to the Falls, it lasts for longer than you might wish (a mile or so?), although it isn't very steep.