X-47B. Interesting - had to search it. Cool plane. About 40 feet long and 30 feet wide with the wings folded up (or removed would be “easy” I would think?) I’m guessing those lanes are about 9 feet wide, plus the shoulder and overhang would make it 30 feet.
There was a thread awhile ago on how they trucked the XR-71 from Burbank(?) to Area 51 on the highway. It took them awhile to widen the road in some spots, move signs, guardrails, etc.
Here is maybe the FR thread I about it, cool stuff:
http://www.freerepublic.com/focus/chat/3015757/posts