PA's mile-marker based system is a lot cleaner (mind you, this is the only way in which PA highways surpass NY ones- in all others they suck). It also means that you'll see much large exit numbers- on a cross state trip like the one we took this week, we saw some pretty big ones. One of which prompted me to quip, "Exit 256 bytes."
256 happens to be 28, which is the exact number of unique values you can hold in eight bits (ie. a byte). I chuckled, and so did Minna.