AASHTO Journal, 13 May 2016
Just as Federal Highway Administrator Greg Nadeau had told state officials to expect, the FHWA has now finalized a trimmed-down list of design criteria for roads on the National Highway System in a change that will simplify many projects and give more design flexibility to state and local governments.
Instead of the 13 design criteria it had applied to all NHS roads since 1985, the FHWA said it will now apply just 10 criteria to design of high-speed roads like interstate highways and other major routes. For low-speed NHS routes, such as urban roads or rural roads that become main streets through smaller cities, it will require designers to use just two criteria.
In doing so, the FHWA said its revisions “help reduce cost and speed up the design of roads and streets located in smaller towns and cities … [and] allow state and local engineers to develop flexible design solutions that meet local travel needs and goals.”
Nadeau, in a speech to AASHTO’s 2015 annual meeting in Chicago on Sept. 28, had told state department of transportation officials to expect a review of the longstanding design criteria.
On Oct. 7, his agency published a Federal Register notice that formally launched the review and opened it for two months of public comments, saying it proposed “to refine the focus on criteria with the greatest impact on road safety and operation.”
Now, in a May 5 Register notice, it has ended the process and altered decades of regulatory policy.
The FHWA also issued guidance to clarify when design exceptions are needed, along with documentation requirements, in a guidance memorandum that transmits the policy to its field offices.
Bud Wright, AASHTO’s executive director, said the change in FHWA policy “is a welcome move toward more flexibility for state and local agencies to design roads that fit into their surroundings, balancing safety and operational goals for all modes of travel.”
In the Register notice last October, the FHWA had proposed eliminating three criteria – bridge width, vertical alignment and lateral offset to obstruction – from its list of controlling design criteria. It also proposed renaming three others.
After reviewing comments, the FHWA said the result is that it will apply 10 controlling criteria to the design of “high-speed” roads on the NHS for traffic operating at 50 mph or faster. Those criteria are design speed, lane width, shoulder width, horizontal curve radius, super-elevation rate, stopping sight distance, maximum grade, cross slope, vertical clearance and design loading structural capacity.
On “low-speed,” non-freeway NHS roads designed for traffic below 50 mph, the FHWA will now require only the criteria of design speed and design loading structural capacity.
The FHWA added: “The overwhelming support for changes to the controlling criteria indicate that the changes will support agency and community efforts to develop transportation projects that support community goals and are appropriate to the project context.”