Motor Carrier Officers (MCO) enforce laws related to commercial vehicles. The deputy's job is setting up portable weight inspection spots, inspecting the mechanical safety of trucks, making sure hazardous loads are properly packaged, and that other loads are secured properly. The MCO enforces Oregon Revised Statutes and Oregon Administrative Rules, as well as the Federal Motor Carrier Safety Regulations. The MCO is a Federal Motor Carrier Safety Administration (FMCSA) North American Standard Level 1 Motor Carrier Inspector, accredited by the Commercial Safety Alliance.
In the 1970s, Washington County Land Use and Transportation transferred its equipment and funding for inspecting commercial trucks to the Sheriff's Office and deputies were specially trained as Motor Carrier Enforcement Officers. Although many agencies have part-time Commercial Motor Vehicle (CMV) inspectors, the Sheriff's Office currently has three Level 1 inspectors, two who are full-time police-certified inspectors with the MCO program, dedicated to commercial vehicle enforcement throughout Washington County.