Oh, and there is never enough warning before freeway exits

Except on roads with substandard exit spacing (sadly, most urban highways) the standard is 2 miles advanced warning including which side you'll be exiting from (again, if you're exiting from other than the right, that's also substandard, and if they do substantial work to the road, they get to move the exit from one side to the other).

At 70mph, you're still talking 1.68 minutes between the sign and the exit, not counting the amount of time before the sign that you see it.