Bridge design follows AASHTO LRFD Bridge Design Specifications with VA state-specific amendments. Design live load is HL-93 per AASHTO LRFD. Bridge width shall match the approach roadway width plus standard barrier widths. Minimum vertical clearance: Interstate 16.5 ft, other routes 16.0 ft (new) or 14.5 ft (reconstruction). Hydraulic design for bridges uses the 100-year flood for design and 500-year flood for structural integrity check.
References: AASHTO current edition, VA 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: VDOT Highway Design Manual, 2024 Edition. Pages 25–26 of 37.