JavaScript must be enabled in order to use this site.Please enable JavaScript in your browser and refresh the page. D1.D.1 AASHTO (ASD) The design of structural steel members in accordance with the AASHTO Standard Specifications for Highway Bridges, 17th edition has been implemented. D1.D.1.1 General D1.D.1.2 Allowable Stresses D1.D.1.3 AASHTO (ASD) Design Parameters Parent topic: D1.D. American Codes - Steel Design per AASHTO Specifications Related topics V. AASHTO 17th Ed ASD - Design Frame