The pit express looks great, but is a bit spendy.  I saw some of the first ones made, they had hydraulics to raise them, and they moved on wheels, didn't lift off the ground.  I never saw one in operation, but it looked like it would move without too many problems.  Only downside I saw was possibly the trailing pit express might be a bit wide going down the road, but remember I only saw one on display, never saw how it actually moved.

There are several drive-over movable pits available now, some move separate from the auger and dump into the auger end.  I liked the idea of not having to move the pit for each hopper of the semi.  Not a bad job in good weather, but with mud and snow, can be backbreaking.