Just imagine all the land that could be freed up if you cut & cover 35 with decks, not to mention reconnecting neighborhoods. Rainey wouldn't be this isolated clusterf*** that's difficult to get in and out of. A tunnel would obviously be better, but that will never happen. Decks every so often eliminate the need for tunnel infrastructure.
Dallas and Columbus OH, among others, have done this on some of their freeways.
Although Texas has this extreme fascination with parallel frontage feeder roads that make bloated interstates twice as wide as necessary. Most other states don't build highways this way.