"The [Iowa] primary highway system makes up over 9,000 miles (14,000 km), a mere 8 percent of the U.S. state of Iowa's public road system." [0]
So while laudable, it would be very nice if North Carolina followed suit with its ~79,000 miles of maintained roads (largest of any state) [1]. But I doubt that would happen, my friend at NCDOT says the culture emphasizes building new roads (or the ones that get wiped out by hurricanes out on the outer banks), and change intersections in a manner that borders on the whimsical.
We like to build roads in challenging places, it seems [2].
North Carolina does not have the most maintained roads of any state, they have "largest state maintained highway network in the United States."
This is a function of them choosing to maintain roads at the state level instead of the county level. If you look at road miles by state [0] regardless of the actual entity that maintains them, they are 16th.
Their highway network is still pretty large, though.
Texas also has an all-state-maintained system (except for toll roads, which are private, but the free service roads are still state-maintained... and Texas tends to favor adding service roads wherever possible), and their road network is the second-largest state-maintained highway network in the US. When you compare the physical size of the two states, NC really comes off as having an excessive amount of roads.
Texas as roughly 5x the size of NC by landmass, and has approximately 3x the number of road miles. However, NC is more densely populated than TX. If you look at it by road mile per person they are almost identical.
And North Carolina places a particular emphasis on paving every road. It's pretty much impossible to find a public road in NC that has street signs and stop signs but is unpaved. The only ones I can think of offhand are in state parks. By contrast, on a recent trip through western Maryland there were about two major roads that were paved for their entire length and the rest reverted to gravel in the more remote areas.
This is a function of them choosing to maintain roads at the state level instead of the county level. If you look at road miles by state [0] regardless of the actual entity that maintains them, they are 16th.
[0] http://blog.cubitplanning.com/2010/02/road-miles-by-state/