Section 39-09-04.1 - Special speed limitations1. No person may drive any vehicle equipped with solid rubber tires at a speed greater than a maximum of ten miles [16.09 kilometers] per hour.2. No person may drive a vehicle over any bridge or other elevated structure constituting a part of a highway at a speed which is greater than the maximum speed which can be maintained without hazard to such bridge or structure, when such structure is signposted as provided in this section.3. The director or other authority having jurisdiction may conduct an investigation of any public bridge, causeway, or viaduct and if the director finds that such structure cannot safely withstand the traveling of vehicles at the speed otherwise permissible under this chapter, such director or other authority shall determine and declare the maximum speed of vehicles such structure can withstand. The director or other authority shall cause or permit signs to be erected and maintained at a distance of one hundred feet [30.48 meters] from each end of such structure. Such signs must state the maximum speed permissible over such structure. The findings and determination of the director or other authority are conclusive evidence of the maximum speed which can be maintained without hazard to any such structure.