Yeah, there is traffic shaping in place. You can't quite see it from the camera, but in places the track does narrow down somewhat. Plus, don't forget about the throttling that's in place, as if you try and corner too fast you'll come off the track and that's bad.
But being serious, its part of the team incentive thing that they have going in the CSC. So the track is only really used a few times each month, when one person from each team is put forward to represent the team and try to win the trophy.