The Olympics generated a lot of interest in BMX, but compared to this course, it was a sprint.  The only thing the record size track built for the ABA BMX Grand Nationals lacked was the dizzyingly high start gate.  This gives you some idea of the scope of the track.  There are a lot more pics of the construction here.
To watch video, check out go211.com’s coverage.  It’s crazy how fast these guys and girls cover the 1200+ feet of track.