When signs are erected giving notice thereof, no person shall operate any motor vehicle capable of being licensed to carry over 12,000 pounds gross weight, at any time upon any of the streets, or portions of streets, described in Schedule VIII, attached hereto and made part of this chapter, except that such vehicles may be operated thereon for the purpose of delivering or on-loading materials or merchandise, but only by entering such street at the intersection nearest the destination of the vehicle, and proceeding thereon no farther than the nearest intersection thereafter. (Ord. 382 § 2, 1972; Ord. 282 § 93, 1968).