One of my favorite ways of travel is the overpass, it's like the metro for me except less claustrophobia from the underground. I felt that the overpass never really got that much attention, there's occasional detail on some areas in the overpass but i think it would be interesting if more content was added, more spawns on the overpass that include raider camps, gunner camps, monsters roaming on the overpass; it would make traveling on the overpass as fun as traveling on the ground. I normally use a jetpack to jump the giant spaces between the overpasses but maybe having some occasional bridges would be nice but leaving some areas to require a jetpack for further exploration. Even maybe adding a small settlement to have on the overpass would be fun. Whatever adds more stuff to the overpass would be interesting. Heck! Making the overpass area a DLC on its own would be hella fun to have!