Alabama US 80

[US71]

Has that theory ever been proven?  Have studies been done that have show that an Interstate brings more prosperity than a 4 lane US or state highway?

I'm a bit late responding to this but Greenland, AR bent over backwards for a Phillips 66/McDonald's built at I-540 (previously they only had a run down Shamrock Mini-Mart on US 71 and no fast food), then bent over backwards again to attract a Sonic across from McDonald's . So at least in Greenland's case, the Interstate (supposedly) brings more prosperity.  Though if 540 had never been built, I wonder if McDonald's would eventually built a location in town?

Ozark, AR is another example: about 20 years ago, they annexed a bunch of property along I-40 and extended utilities out there to attract a Love's, a Days Inn and a KFC/Taco Bell... mostly because the Interstate was killing the local businesses on US 64.