Standard cross section elements include traveled way, shoulders, medians, slopes, and clear zones. ADOT standard lane width is 12 feet for design speeds ≥50 mph and 11 feet for lower speeds. Shoulder widths: Interstate 10 ft paved; arterial 8 ft; collector 4-6 ft. Median widths determined by access control requirements and barrier warrant analysis per the AASHTO Roadside Design Guide.
References: AASHTO current edition, AZ Standard Specifications, FHWA Technical Advisories, and applicable federal regulations (23 CFR). Contractors shall maintain current copies of all referenced standards on the project site.
Source: ADOT Highway Design Manual, 2024 Edition. Pages 9–10 of 37.