More life-tracking madness

Timothy Reichard has a site wherein one can keep track of which Interstate highways one has travelled on. You can look at how I've done on a state-by-state basis here; I've driven (or ridden) on 23% of the country's Interstates.
Putting together your list of highways isn't simple. Besides figuring out everywhere you've been, you'll have to use his Highway Browser to figure out what the abbreviations are for all of the exits that determine the start and stop points for your segments. If you like highways like I do, though, it'll be a fun process.