1. No motor vehicle, unladen or with load, operating exclusively within the corporate limits of cities containing seventy-five thousand inhabitants or more or within two miles of the corporate limits of the city or within the commercial zone of the city shall exceed fifteen feet in height.

2. No motor vehicle operating exclusively within any said area shall have a greater weight than twenty-two thousand four hundred pounds on one axle.

3. The “commercial zone” of the city is defined to mean that area within the city together with the territory extending one mile beyond the corporate limits of the city and one mile additional for each fifty thousand population or portion thereof provided, however:

(1) The commercial zone surrounding a city not within a county shall extend twenty-five miles beyond the corporate limits of any such city not located within a county and shall also extend throughout any county with a charter form of government which adjoins that city and throughout any county with a charter form of government and with more than two hundred fifty thousand but fewer than three hundred fifty thousand inhabitants that is adjacent to such county adjoining such city;

(2) The commercial zone of a city with a population of at least four hundred thousand inhabitants but not more than four hundred fifty thousand inhabitants shall extend twelve miles beyond the corporate limits of any such city; except that this zone shall extend from the southern border of such city’s limits, beginning with the western-most freeway, following said freeway south to the first intersection with a multilane undivided highway, where the zone shall extend south along said freeway to include a city of the fourth classification with more than eight thousand nine hundred but less than nine thousand inhabitants, and shall extend north from the intersection of said freeway and multilane undivided highway along the multilane undivided highway to the city limits of a city with a population of at least four hundred thousand inhabitants but not more than four hundred fifty thousand inhabitants, and shall extend east from the city limits of a special charter city with more than two hundred seventy-five but fewer than three hundred seventy-five inhabitants along State Route 210 and northwest from the intersection of State Route 210 and State Route 10 to include the boundaries of any city of the third classification with more than ten thousand eight hundred but fewer than ten thousand nine hundred inhabitants and located in more than one county. The commercial zone shall continue east along State Route 10 from the intersection of State Route 10 and State Route 210 to the eastern city limit of a city of the fourth classification with more than five hundred fifty but fewer than six hundred twenty-five inhabitants and located in any county of the third classification without a township form of government and with more than twenty-three thousand but fewer than twenty-six thousand inhabitants and with a city of the third classification with more than five thousand but fewer than six thousand inhabitants as the county seat. The commercial zone described in this subdivision shall be extended to also include the stretch of State Route 45 from its intersection with Interstate 29 extending northwest to the city limits of any village with more than forty but fewer than fifty inhabitants and located in any county of the first classification with more than eighty-three thousand but fewer than ninety-two thousand inhabitants and with a city of the fourth classification with more than four thousand five hundred but fewer than five thousand inhabitants as the county seat. The commercial zone described in this subdivision shall be extended east from the intersection of State Route 7 and U.S. Highway 50 to include the city limits of a city of the fourth classification with more than one thousand fifty but fewer than one thousand two hundred inhabitants and located in any county with a charter form of government and with more than six hundred thousand but fewer than seven hundred thousand inhabitants, and from the eastern limits of said city east along U.S. Highway 50 up to and including the intersection of U.S. Highway 50 and State Route AA, then south along State Route AA up to and including the intersection of State Route AA and State Route 58, then west along State Route 58 to include the city limits of a city of the fourth classification with more than one hundred forty but fewer than one hundred sixty inhabitants and located in any county of the first classification with more than ninety-two thousand but fewer than one hundred one thousand inhabitants, and from the western limits of said city along State Route 58 to where State Route 58 intersects with State Route 7;

(3) The commercial zone of a city of the third classification with more than nine thousand six hundred fifty but fewer than nine thousand eight hundred inhabitants shall extend south from the city limits along U.S. Highway 61 to the intersection of State Route OO in a county of the third classification without a township form of government and with more than seventeen thousand eight hundred but fewer than seventeen thousand nine hundred inhabitants;

(4) The commercial zone of a home rule city with more than one hundred eight thousand but fewer than one hundred sixteen thousand inhabitants and located in a county of the first classification with more than one hundred fifty thousand but fewer than two hundred thousand inhabitants shall extend north from the city limits along U.S. Highway 63, a state highway, to the intersection of State Route NN, and shall continue west and south along State Route NN to the intersection of State Route 124, and shall extend east from the intersection along State Route 124 to U.S. Highway 63. The commercial zone described in this subdivision shall also extend east from the city limits along State Route WW to the intersection of State Route J and continue south on State Route J for four miles.

4. In no case shall the commercial zone of a city be reduced due to a loss of population. The provisions of this section shall not apply to motor vehicles operating on the interstate highways in the area beyond two miles of a corporate limit of the city unless the United States Department of Transportation increases the allowable weight limits on the interstate highway system within commercial zones. In such case, the mileage limits established in this section shall be automatically increased only in the commercial zones to conform with those authorized by the United States Department of Transportation.

5. Nothing in this section shall prevent a city, county, or municipality, by ordinance, from designating the routes over which such vehicles may be operated.

6. No motor vehicle engaged in interstate commerce, whether unladen or with load, whose operations in the state of Missouri are limited exclusively to the commercial zone of a first class home rule municipality located in a county with a population between eighty thousand and ninety-five thousand inhabitants which has a portion of its corporate limits contiguous with a portion of the boundary between the states of Missouri and Kansas, shall have a greater weight than twenty-two thousand four hundred pounds on one axle, nor shall exceed fifteen feet in height.