Here's an FAQ on everything highway-related. Interstate FAQ
Here's a page all about 3-digit Interstates (3di's). 3di
Wikipedia.org, an online open-source encyclopedia, has an interesting section on the Interstate. Interstate Highway
My personal belief is that we should work towards using the IHS for commercial travel or at least make people prove they're going a long distance (like over 75 miles) so that urban/metropolitan regions are not ill-effected by the Interstates as they have been in the past 50 years. Also, rail transit should be integrated into the IHS where feasible. We should be working to tear down Interstate Highways within urban places since they do not benefit the cities themselves. What does everyone think about these thoughts?