A driver may not operate a truck as permitted by Transportation Article, §21-310(f), Annotated Code of Maryland: In a highway work zone as defined in COMAR 11.04.15.01B(5); While transporting hazardous materials as defined by the Hazardous Material Regulation of the U.S. Department of Transportation; While transporting loose materials as defined in Transportation Article, §24-106.1(d), Annotated Code of Maryland; On any road except a controlled access highway as defined in Transportation Article, §21-101(g), Annotated Code of Maryland; and While carrying an overweight or oversize load as defined in Transportation Article, §24-112, Annotated Code of Maryland. No more than two trucks may operate as permitted by Transportation Article, §21-310(f), Annotated Code of Maryland.