We thought our ladies deserved some time with some real grass since they've eaten everything in their run.
So we designed this chicken tractor from looking at many different styles and using materials we had on hand already.

We have two handles on each end for lifting and carrying, and a rope tied to the handles for dragging. We put in their waterer and their dusting box after we get them settled into the area of the yard that we want them in.
Usually we only leave them out for a couple hours. They will all gather at the door of the tractor when they're ready to leave. That's how we can tell they've had enough grassies for the day.
They walk into the the tractor pretty well. Once you get one lady in, the others want to go where she is. Much easier to unload them as they are almost beside themselves to get back into their coop and run. Silly chickens!