All this interstate nonesense is nonsense. If the plebs were able to travel prior to GPS and the internet, why the push now?
It's all about the marketing. If you're pushing a business location to someone, it means something to say, "Located adjacent to I-xx or I-xxx."
Compare that to saying, "Located adjacent to the Bluegrass Parkway, an Interstate-quality limited-access four-lane freeway."
Even though Kentucky's parkways are the functional equivalent of interstates, even if they don't meet some anal-retentive FHWA standard for signing and numbering as an Interstate highway like the median being two feet too narrow, locations along them aren't as marketable for industrial or economic development as a location along an Interstate.
It's more than marketing. Often overlooked is that the Interstate Highway System is a Network of limited access highways to standards that facilitate the best transport of goods and services.
This is why North Carolina had several different Interstate requests for a connection from Charlotte or Greensboro to Wilmington and Morehead City in the 1960s. It eventually evolved to I-40 as we know it today. It really is why Gov. Easley pushed for I-20 to be extended from Florence, SC to Wilmington. I-20 would give the Port of Wilmington direct access to Atlanta allowing it to be more competitive with the Port of Charleston.
This is why the I-69 Corridor is called the NAFTA Corridor and with the Panama Canal Expansion Project this is why so many eastern states are trying to improve their ports and highway systems.
Suppliers & Manufacturers focus more on Interstates because they know the standards of the highway system will allow them to have the best mode of operations on a ground (truck) transport basis. Yes, I know ARC corridors and even regular freeways handle it as well.
Does this mean I thin every freeway should be an Interstate of course not. However, if it meets the standards and can be added/attached to the system - why not? After all, it is a network of highways.
I understand that many don't like Interstate shields on every road but isn't no different than US Highways replacing the Lincoln Highway and The Yellowstone Trail and The Dixie Highway nearly a century ago?
Just imagine if they assigned numbers to the NHS - then many would say, "OH NO, the NHS is killing all the Interstate Numbers!"