U.S. Department of Transportation
Federal Highway Administration
|Subject:||Mitigation Strategies for Design Exceptions||Date:||May 1, 2014|
|From:||/s/ Original signed by: Peter Stephanos for
Walter C. Waidelich, Jr.
Associate Administrator for Infrastructure
|Reply to Attn. of:||HIPA-20|
The Federal Highway Administration (FHWA) published a document entitled Mitigation Strategies for Design Exceptions in 2007. We have received questions about some of the language in this document, specifically language in Chapter 3, intended to clarify when design exceptions are required.
The 23 CFR 625 specifies the standards applicable to projects on the National Highway System. The 23 CFR 625.4(a) adopts two publications of the American Association of State Highway and Transportation Officials (AASHTO): A Policy on Geometric Design of Highways and Streets, 2001 (the 2004 version is allowed by February 23, 2005, memorandum from Dwight A. Horne) and A Policy on Design Standards Interstate System, 2005 (Interstate Standards).
Mitigation Strategies for Design Exceptions provides valuable guidance about the impact design exceptions may have on the safety and operational performance of roadways, and potential mitigation strategies when the 13 controlling criteria are not met. However, it is a guide, and does not constitute a standard, nor does it set forth new policy regarding when design exceptions are required. Where this document conflicts with the adopted AASHTO policies, the AASHTO policies adopted through FHWA regulations govern. If you have any questions or need assistance, please contact firstname.lastname@example.org or email@example.com.
Directors of Field Services
Resource Center Directors
Jeff Jones, Chair AASHTO Technical Committee on Geometric Design