I don't think it's a fake, although it doesn't hurt to question, and the videographer didn't say it was real footage. But I think it is, for two reasons.

1. I traveled from El Paso to Dallas-Fort Worth several times a year in the 1980's. When landing and taxiing to the gate, there was a runway that I could see that had aircraft taxiing on a highway overpass just like in this video. The over pass seemed like it was more elevated, but I'm hardly certain of that.
2. Take a look at Zack Temple's map link of the Oakland Airport in California below. The runway in Dallas is probably similar, but it seemed even more like the video here.

Not fake at all. There are many large airports around the world that have taxiways that go overtop of highways and roads. -ep

Yeah, dummy.

Great map! Thanks!