oh this is cool.
I did think for a 2 day setup and 1/2 day takedown it wasn't a huge efficiency saving but it is if you move it down the road at the same time.
As the comment above mentions, safety is a huge factor too.
During the night, there will be 1 lane open in each direction (one on the side of the bridge, and one on the opposite carriageway), so the bridge can be moved.
I guess it's theoretically possible to engineer a bridge that can move with traffic on it.
But this bridge is engineered with solid feet for taking traffic loads. The wheels are only extended for movement and wouldn't be able to take the load of traffic.