Well, if its a desolate location, i could see. Only problem i think is environmental damage it would cause as it rolls around. If it has pre-parpared road, it won't be so bad. However, what would be the point. There isn't much need for roving city, its would be bad for commerce anyways if its into trading. Mobile mining town, i could see, but then again you got the environmental problems this thing would be causing. Sewage, water needs, food supply, you carry so much for vertical farm if your trying relieve the food constrants.
In Battletech, on a desolate world or environmentally challenging one. I could see it, though i can picture very big target for pirates or any opposing forces to shoot holes into. Ares treaty or not, mobile town / city isn't practical. Then again...Battletech usually ignores those things. :D