1. It shall be the duty of the sheriff of each county or city to see that the provisions of sections 304.170 to 304.230 are enforced, and any peace officer or police officer of any county or city or any highway patrol officer shall have the power to arrest on sight or upon a warrant any person found violating or having violated the provisions of such sections. Beginning January 1, 2009, only law enforcement officers that have been approved by the Missouri state highway patrol under section 304.232, members of the Missouri state highway patrol, commercial vehicle enforcement officers, and commercial vehicle inspectors appointed under subsection 4 of this section shall have the authority to conduct random roadside examinations or inspections to determine compliance with sections 304.170 to 304.230, and only such officers shall have the authority, with or without probable cause to believe that the size or weight is in excess of that permitted by sections 304.170 to 304.230, to require the driver, operator, owner, lessee, or bailee, to stop, drive, or otherwise move to a location to determine compliance with sections 304.170 to 304.230. Notwithstanding the provisions of this subsection, a law enforcement officer not certified under section 304.232 may stop a vehicle that has a visible external safety defect relating to the enforcement of the provisions of sections 304.170 to 304.230 that could cause immediate harm to the traveling public. Nothing in this section shall be construed as preventing a law enforcement officer not certified under section 304.232 from stopping and detaining a commercial motor vehicle when such officer has probable cause to believe that the commercial motor vehicle is being used to conduct illegal or criminal activities unrelated to violations of sections 304.170 to 304.230. In the course of a stop, the law enforcement officer shall identify to the driver the defect that caused the stop. If the vehicle passes a comprehensive roadside inspection, the law enforcement officer, state highway patrolman, or other authorized person shall issue such vehicle a commercial vehicle safety alliance inspection decal to be affixed to the vehicle in a manner prescribed by the commercial vehicle safety alliance. The superintendent of the Missouri state highway patrol shall promulgate rules and regulations relating to the implementation of the provisions of this section. Any rule or portion of a rule, as that term is defined in section 536.010, that is created under the authority delegated in this section shall become effective only if it complies with and is subject to all of the provisions of chapter 536 and, if applicable, section 536.028. This section and chapter 536 are nonseverable and if any of the powers vested with the general assembly pursuant to chapter 536 to review, to delay the effective date, or to disapprove and annul a rule are subsequently held unconstitutional, then the grant of rulemaking authority and any rule proposed or adopted after August 28, 2008, shall be invalid and void.

2. Any peace officer approved under section 304.232 or any highway patrol officer is hereby given the power to stop any such conveyance or vehicle as above described upon the public highway for the purpose of determining whether such vehicle is loaded in excess of the provisions of sections 304.170 to 304.230, and if he or she finds such vehicle loaded in violation of the provisions thereof he or she shall have a right at that time and place to cause the excess load to be removed from such vehicle; and provided further, that any regularly employed maintenance man of the department of transportation shall have the right and authority in any part of this state to stop any such conveyance or vehicle upon the public highway for the purpose of determining whether such vehicle is loaded in excess of the provisions of sections 304.170 to 304.230, and if he or she finds such vehicle loaded in violation of the provisions thereof, he or she shall have the right at that time and place to cause the excess load to be removed from such vehicle. When only an axle or a tandem axle group of a vehicle is overloaded, the operator shall be permitted to shift the load, if this will not overload some other axle or axles, without being charged with a violation; provided, however, the privilege of shifting the weight without being charged with a violation shall not extend to or include vehicles while traveling on the federal interstate system of highways. When only an axle or tandem axle group of the vehicle traveling on the federal interstate system of highways is overloaded and a court authorized to enforce the provisions of sections 304.170 to 304.230 finds that the overloading was due to the inadvertent shifting of the load changing axle weights in transit through no fault of the operator of the vehicle and that the load thereafter had been shifted so that no axle had been overloaded, then the court may find that no violation has been committed. The operator of any vehicle shall be permitted to back up and reweigh, or to turn around and weigh from the opposite direction. Any operator whose vehicle is weighed and found to be within five percent of any legal limit may request and receive a weight ticket, memorandum or statement showing the weight or weights on each axle or any combinations of axles. Once a vehicle is found to be within the limits of section 304.180 after having been weighed on any state scale and there is no evidence that any cargo or fuel has been added, no violation shall occur, but a presumption shall exist that cargo or fuel has been added if upon reweighing on another state scale the total gross weight exceeds the applicable limits of section 304.180 or 304.190. The highways and transportation commission of this state may deputize and appoint any number of their regularly employed maintenance men to enforce the provisions of such sections, and the maintenance men delegated and appointed in this section shall report to the proper officers any violations of sections 304.170 to 304.230 for prosecution by such proper officers.

3. The superintendent of the Missouri state highway patrol may assign qualified persons who are not highway patrol officers to supervise or operate permanent or portable weigh stations used in the enforcement of commercial vehicle laws. These persons shall be designated as commercial vehicle inspectors and have limited police powers:

(1) To issue uniform traffic tickets at a permanent or portable weigh station for violations of rules and regulations of the division of motor carrier services of the highway and transportation commission and department of public safety, and laws, rules, and regulations pertaining to commercial motor vehicles and trailers and related to size, weight, fuel tax, registration, equipment, driver requirements, transportation of hazardous materials and operators’ or chauffeurs’ licenses, and the provisions of sections 303.024 and 303.025;

(2) To require the operator of any commercial vehicle to stop and submit to a vehicle and driver inspection to determine compliance with commercial vehicle laws, rules, and regulations, the provisions of sections 303.024 and 303.025, and to submit to a cargo inspection when reasonable grounds exist to cause belief that a vehicle is transporting hazardous materials as defined by Title 49 of the Code of Federal Regulations;

(3) To make arrests for violation of subdivisions (1) and (2) of this subsection. Commercial vehicle inspectors shall not have the authority to exercise the powers granted in subdivisions (1), (2) and (3) of this subsection until they have successfully completed training approved by the superintendent of the Missouri state highway patrol; nor shall they have the right as peace officers to bear arms.

4. The superintendent of the Missouri state highway patrol may appoint qualified persons, who are not members of the highway patrol, designated as commercial vehicle enforcement officers, with the powers:

(1) To issue uniform traffic tickets for violations of laws, rules and regulations pertaining to commercial vehicles, trailers, special mobile equipment and drivers of such vehicles, and the provisions of sections 303.024 and 303.025;

(2) To require the operator of any commercial vehicle to stop and submit to a vehicle and driver inspection to determine compliance with commercial vehicle laws, rules, and regulations, compliance with the provisions of sections 303.024 and 303.025, and to submit to a cargo inspection when reasonable grounds exist to cause belief that a vehicle is transporting hazardous materials as defined by Title 49 of the Code of Federal Regulations;

(3) To make arrests upon warrants and for violations of subdivisions (1) and (2) of this subsection. Commercial vehicle officers selected and designated as peace officers by the superintendent of the Missouri state highway patrol are hereby declared to be peace officers of the state of Missouri, with full power and authority to make arrests solely for violations under the powers granted in subdivisions (1) to (3) of this subsection. Commercial vehicle enforcement officers shall not have the authority to exercise the powers granted in subdivisions (1), (2) and (3) of this subsection until they have successfully completed training approved by the superintendent of the Missouri state highway patrol and have completed the mandatory standards for the basic training and licensure of peace officers established by the peace officers standards and training commission under subsection 1 of section 590.030. Commercial vehicle officers who are employed and performing their duties on August 28, 2008, shall have until July 1, 2012, to comply with the mandatory standards regarding police officer basic training and licensure. Commercial vehicle enforcement officers shall have the right as peace officers to bear arms.

5. Any additional employees needed for the implementation of this section shall be hired in conformity with the provisions of the federal fair employment and antidiscrimination acts.

6. Any part of this section which shall be construed to be in conflict with the axle or tandem axle load limits permitted by the Federal-Aid Highway Act, Section 127 of Title 23 of the United States Code (Public Law 85-767, 85th Congress) shall be null, void and of no effect.

7. The superintendent may also appoint members of the patrol who are certified under the commercial vehicle safety alliance with the power to conduct commercial motor vehicle and driver inspections and to require the operator of any commercial vehicle to stop and submit to said inspections to determine compliance with commercial vehicle laws, rules, and regulations, compliance with the provisions of sections 303.024 and 303.025, and to submit to a cargo inspection when reasonable grounds exist to cause belief that a vehicle is transporting hazardous materials as defined by Title 49 of the Code of Federal Regulations.