Congressional Mandate
In 1993, Congress directed the US DOT to “revise the MUTCD to include a standard for a minimum level of retroreflectivity that must be maintained for pavement markings and signs, which shall apply to all roads open to public travel.“ Since the 1993 directive, FHWA has focused on developing a rational set of minimum requirements for sign and pavement marking retroreflectivity. Since that time significant strides have been made in developing sound and practical minimum requirements, as well as means to facilitate their implementation. United States Department of Transportation and Related Agencies Appropriation Act of 1993, Public Law 102-388,106 Statute 1520, Section 406.
