The city shall have markings painted or placed upon the curb or upon the street in four-hour parking zones for the purpose of designating the parking space for a vehicle, and vehicles shall be parked within the lines or markings so established. It shall be unlawful and a violation of this division to park any vehicle across any such line or marking or to park such vehicle in such position that it shall not be entirely within the area so designated by such lines or markings.