Examples of typical strenuous activity, include frequently lifting and carrying objects weighing up to 100 pounds., carrying and rolling rocks and logs, moving rocks of several tons with rock bars, using hammers to crush or shape rock, and using shovels extensively; frequently walks up to 20 miles daily; and must not have potential emergency medical problems that could complicate work in remote areas for extended periods of time. Prior to your first official motor vehicle operation, and again every year thereafter (or more frequently if management determines such need exists), you will be required to sign an affidavit certifying to your possession of a valid State issued drivers license that is current and has not been revoked, suspended, canceled, or otherwise disqualified in any way to prohibit your operation of a motor vehicle.