"There's a road I'd like to tell you about...

[specialist8]

Veech, keep in mind that those even/odds rules apply to the [b]majority[\b] of how the route/highway is laid out. For example, I90/94 clearly goes north and south for a good stretch in Illinois, but the majority of the route lies east-west. Also, wikipedia has some insightful info here:

Freeways that go into cites are called spur routes and start with an odd number. Freeways that go around cities are called loop routes and start with an even number. The last two digits in a spur or a loop route are the same as the freeway it started from.