which one is the LONGEST? Looks like I-80 to me.
Yes, they are odd and even for vertical and horizontal routes. And Interstate circle beltways are 3 digits.
I wonder why Interstate 80/90 as it runs thru northern Ohio in the Cleveland area becomes a TURNPIKE with tolls ????
It does appear there may have been some actual PLANNING on the numbering of the interstate system under Eisenhower I believe it was..
That is interesting De!