Safety & Liability
Highway Standards & Policies
The AASHTO Green Book
Most state and local safety policies are based on the guidance recommended by the American Association of State Highway and Transportation Officials (AASHTO)—generally referred to by its popular name pronounced “ASH-tow”.
The AASHTO guidance for highway design, A Policy on Geometric Design of Highways and Streets, is known most popularly as the Green Book. The purpose of the Green Book is to recommend safe and efficient practices for the design of roadways. The recommendations contained in the Green Book are based on extensive research and study, and generally provide a range of acceptable design criteria based on the type of roadway and the expected traffic volume for the facility. The FHWA has adopted the Green Book as the minimum standard for projects on the National Highway System (NHS), which includes the Interstate System and other selected principal routes and connectors to intermodal facilities (check with your state transportation department to see if your historic road is a part of the NHS). For all other projects, developed with Federal-aid funds or not, design is directed by the standards adopted by the state or local government. Almost every state and the majority of local governments have adopted the Green Book in whole or in part for use on their own projects. Remember the guidelines and recommendations contained in the Green Book do not become “standards” until adopted by your state or local government.
When working with the Green Book, it is important to remember the flexibility contained in the range of criteria recommended. As noted, this flexibility is at the discretion of your state or local transportation department. It should also be noted, under special circumstances, that solutions outside the recommended range may be sanctioned by the FHWA for projects on the NHS. This special approval, known as a “design exception,” is based on a clearly articulated need and demonstration that the proposed solution will not lead to a safety problem.
Section 4(f) of the Department of Transportation Act of 1966, 49 U.S.C. § 303, is a substantive requirement that prohibits federal approval or funding of any transportation project that requires the “use” of any historic site, public park, recreation area, or wildlife refuge unless there is “no feasible and prudent alternative to the project,” and “all possible planning to minimize harm to the project” has been addressed (DOT Act, 1966, Sec 4[f]). The use of Section 4(f), long a powerful tool for the preservation of historic roads, was modified in 2005 so that it may be fulfilled in certain situations by the Section 106 process. If there is a finding of “no adverse effect” under Section 106, even with a minor use of an historic property and the SHPO concurs, there is no further requirement for a 4(f) evaluation. An adverse effect finding, on the other hand, requires the agency to seek options/flexibilities for the preservation of an affected historic property, including a historic road (or other historic resources) negatively impacted by a federally funded highway project. In other words, where 106 and 4(f) were once invoked concurrently, 4(f) is now applied only if the Section 106 process results in an adverse effect to the historic property in question. Section 106 is the first course of action for historic properties impacted by federally funded transportation projects.
dvocacy organizations were one of the critical forces behind the development of our modern highway network. Through boosterism, research, planning and political action during the Good Roads era, these organizations served an important role in defining need, design and use.
Today, both formal and informal advocacy organizations are being formed and planned around our nation’s historic roads. Some serve as recorders of history and popular culture, while others are actively involved with the design and management of historic facilities. If properly developed and organized, they may become credible and respected partners providing valuable assistance to the management entity.
An advocacy organization can record, research and document a road’s history; assist the managing organization in reporting safety problems, vandalism, and maintenance issues; and serve as an independent “watchdog” organization to ensure that state and federal policies and reviews are being upheld. Naturally, advocacy organizations are the principal generator and organizer of community outreach through special or commemorative events, public awareness projects, community publications, scholarly research and interpretive programs. Depending on the structure of the advocacy organization and its relationship with the managing agency, advocacy organizations can also lobby, campaign or fundraise on behalf of the historic road, or provide volunteer labor for clean-up projects, traffic surveys and restoration projects. For longer historic routes and corridors, they may serve as a unifying voice for multi-state or regional historic roads.
s historic roads are increasingly recognized as unique resources deserving of special management considerations and administrative accommodation, a number of states have issued policy statements that direct transportation departments to undertake specific actions or activities related to a historic road or roads. Policy statements carry legislative authority and require legal actions that can greatly assist in the proper analysis and management of a historic road. The following represent a wide range of policy statements and management strategies for historic roads.
Connecticut: Policy for the Merritt Parkway (1994)[PDF of Policy Statement| Coming Soon]
Hawaii: A Bill to Support Flexible Design on Hawaii’s Roads (2006)[PDF of Policy Statement | Coming Soon]
New Jersey: Historic Roads Inventory[PDF of Policy Statement | Coming Soon]
Oregon: State Policy to Preserve the Historic Columbia River Highway (1995)[PDF of Policy Statement | Coming Soon]