US interstate system as minimum spanning tree

I had a dream in which the Eisenhower interstate system was designed as a minimum spanning tree. Less pavement, I guess, but more driving.

To quantify that assessment, Wikipedia reports that the US interstate highway system is 48,890 miles of road and that it was originally proposed to connect all US cities with a population of over 50,000, though the Smithsonian National Museum of American History says 100,000. According to this Wikipedia page, there are 330 cities of more than 100,000 people in the 2020 census. Here's a minimum spanning tree of those cities, excluding those in Alaska and Hawaii:

That's a highway system with only 16,035 miles of pavement, one-third that of the current highway system. Some of the reduction is due to fewer roads, some is due to connecting cities by straight lines instead of following the easiest terrain.

Of course, the downside to using a minimum spanning tree is that some cities are relatively close to each other geographically but far from each other by road, requiring longer trips between those cities, at least if traveling by interstate. The worst case is traveling from Mobile, Alabama to Montgomery, Alamaba, a straight-line distance of 153 miles, but which this highway system extends to almost 3,000 miles, 18 times longer, having to route west to Oklahoma City, north to South Bend, Indiana, then south through Nashville, Tennessee: