I've thought that for years, but it's probably not the technology, it's probably the cost. Over the mountains would probably be cheaper than through the mountains. The other issues are probably getting the land rights, land conservation, animal rights, etc.
There's always US-50 "the loneliest highway" all the way through Nevada, past Fallon, until it runs into I-80. It might be less expensive for them to turn 50 into an interstate. Whether they'd do it or not, is anyone's guess. Hah.