Someday we'll go metric and we'll have to pay for yet another conversion. Bah.

Given the recently-recharged disdain for the French that exists in America, I don't see "Systeme Internationale" taking off in the U. S. of A. anytime soon.

I also hate mileage-based exit numbers. The one good aspect I can think of (besides the obvious "you know that if you get on at exit 150 and you're getting off at exit 176, you're travelling 26 miles" benefit) is that you don't have to re-number if exits are added. This actually happens on occasion. The way it's usually dealt with is to add suffixes to the exit numbers like "Exit 7A" or whatever. But that's really lame. The mileage exit numbers would seem to avoid this, unless somehow there are 2 distinct exits within the same mile.

The mileage numbering is REALLY screwy on the PA Turnpike, because of the Northeast Extension. What I think they're doing is taking the easternmost mile number (let's say it's 310) and making that the start of the NE Extension mile numbers. So if you get on the PA Turnpike near where the Northeast Extension comes in, and jump on the NE Extension, you'll "warp" past like 100 miles. Stupid.