The American Association of State Highway and Transportation Officials is the federal agency which oversees highway planning, construction, engineering and maintenance, as stated in the agency's mission overview. Construction specifications are defined for every detail, from base compaction to signage and everything between.Continue Reading
Both federal and state Departments of Transportation develop, set, review and enforce highway construction standards that define and standardize every detail of engineering and construction. The Aashto is comprised of representatives from representatives of every state's Department of Transportation, as well as representatives from Puerto Rico and the District of Colombia, states the association's website.
National highway standards are produced by this collaborative agency, through which individual states can further develop specifications specialized for that state's local geographic conditions. Examples of such locally tailored highway construction standards are the various earthquake-compliance standards mandated by the California Department of Transportation officially shortened as "Caltrans." Per Caltrans' Seismic Design Criteria 1.7, requirements may vary, however bridges must withstand a minimum Richter magnitude of 6.5, according to the department's Office of Earthquake Engineering.
Lesser construction specifications for details such as signage are also mandated by state agencies. For example, regulatory, warning and guide signs must be retroflective, or otherwise remained illuminated at the same level during day and night, according to Caltrans.Learn more about Law