That is quite the coop coming together. Being an ex trucker, I might have some similar concerns as others about weight, axle placement and such.
Somehow it looks a bit precarious to me.
When it's finished, you might want to find a truck stop somewhere with scales. For about $5 you can weigh...
I would totally do this so I could take my chickens just to keep an eye on them when I went to walmart or the grocery.
Or maybe on a trip to Baja or something.