[EricH]

I have no experience with powered driving carts. However, here's some of the obstacles you will need to worry about: Wire guards (the main one; usually about 1-3 inches high and close to a foot long) and the occaisional ramp. And, of course, crowds. Assuming tank steering, you may want casters. For raising the bot, you can raise the whole cart (which doesn't work too well) or use a scissors lift.