A mobile device which supports apparatus for site imaging while in transit is disclosed. The mobile device comprises a plurality of wheels, an imaging unit having at least one camera and supported above the head of an operator, a control unit for monitoring and controlling operation of each camera and of generated image data so as to produce an interactive movie, a steering device for navigating the mobile device within the site, a measuring device for measuring the relative displacement of the mobile device, a computer for determining the relative location and orientation of the mobile device within the site and for processing data, and a monitor. In one embodiment, two of the wheels are self-aligning caster wheels, and a mechanism and method for preventing drifting during the initial advancement of the mobile device are provided. A rotating mechanism is actuated until each caster wheel achieves a trailing position.