Visible crew/equipment: Just after the bus has got on to the empty freeway, there is a long shot of the bus driving off. In this shot, the camera's shadow can be seen to the extreme right of the shot. The shadow is faint, but it is there. (00:51:30)
Visible crew/equipment: In the scene after the bus gets off the on ramp and hits a bunch of cars, there is a rear facing shot. The shadow of the camera that is attached to the bus is visible during most of the shot.






Answer: If they had, there might have been the possibility that to get to these routes they would have to go down a different road and depending on which route they take they might have to slow down to make the turn which would likely cause the bus to drop below 50 mph. Better to just keep going straight and keep the bus going. There's also the possibility that had they taken a different route, they would have to deal with a lot of traffic especially if there was traffic stopped at a red light. By using the highway, there'd be no traffic lights and less traffic to deal with.