I don’t think we’ve ever thought that far ahead. In Germany the roadbeds can be 8 plus feet thick with different materials layered. The autobahn runways are placed where you have a couple miles of flat land. The four lanes come together to form one strip and metal dividers are inserted down the center. They are high enough so oncoming headlights are not visible, with the hammer head and fuel tanks on one end of that strip, big enough to enable refueling and rearming a couple aircraft at a time. In case of an emergency they could remove those two miles of dividers in a few hours with a couple bobcats or fork lifts. We’re too far away from our adversaries to worry about having to reconstitute our fighter force. It would go ICBMs long before it got to that point.
Just something I was thinking about. You’d think the guys designing the thing would get the bright idea that, hey....this is a long flat stretch....what if we made it so you can knock down the lighting standards and signs, reinforce the roadbed, and have a potential airstrip? Seems like you could get a lot done just about anywhere you could get KC-135s and C-130s on the ground. I suppose with all the ICBMs the Soviets had pointed at us, it would just be one more target. Disrupting the interstates would probably be a goal, regardless.