Publication Number: FHWA-RD-02-012
Date: July 2002

Wanted: A Smoother Ride

In a recent survey asking motorists what they wanted in their highways, the Federal Highway Administration (FHWA) found that the way to a driver's heart is lined with smooth pavement. Road condition was cited as the public's number one criteria for satisfaction. This fact helped spawn FHWA's pavement smoothness initiative, which calls for the improvement of the national highway network's smoothness level by 2008.

Achieving a high level of smoothness during initial construction is a key measure of pavement quality. In addition to influencing driver satisfaction, pavement smoothness affects driver safety and mobility. Smoother roads also increase fuel efficiency and decrease vehicle wear. A National Cooperative Highway Research Program analysis showed that improved smoothness extends a pavements' performance life by up to 50 percent.

FHWA is working with State highway agencies across the country to implement State smoothness programs. An effective smoothness program requires the following components:

• Processes that identify the best projects for maintaining and improving the pavement smoothness of the entire highway network.
• A method of specifying pavement smoothness during initial construction.
• A method of measuring pavement smoothness during initial construction.
• Tools for contractors to build smooth pavements.
• Timely maintenance and strict enforcement of smoothness specs.

One example of a State success story is the Georgia Department of Transportation, which has consistently maintained one of the smoothest highway networks in the Nation. Georgia implements an effective preventative maintenance and treatment program that corrects minor problems before they become major ones and keeps costs down. It also awards construction contracts quickly, which facilitates timely maintenance, and sets and enforces strict smoothness specifications.

Achieving a high level of smoothness during initial construction is a key measure of pavement quality.

As part of its smoothness initiative, FHWA has developed specifications for measuring pavement smoothness at initial construction. These specifications were presented to the American Association of State Highway and Transportation Officials' (AASHTO) Joint Task Force on Pavements at its annual meeting in May. The Task Force approved the submission of the specifications to the AASHTO Subcommittee on Materials, with a decision on adoption expected this summer.

In addition to the specifications, FHWA will release two reports this month, Hot Mix Asphalt Pavement Smoothness: Characteristics and Best Practices for Construction (Publication No. FHWA-IF-02-024) and Portland Cement Concrete Pavement Smoothness: Characteristics and Best Practices for Construction (Publication No. FHWA-IF-02-025). Both reports provide concise technical information on the best practices for measuring, specifying, and achieving pavement smoothness. And to assist States in transitioning from their current pavement smoothness practices to the proposed AASHTO guidelines, FHWA has put together a Pavement Smoothness Index Relationships guide.

Mark Swanlund, a pavement design engineer in FHWA's Office of Pavement Technology, says, "Smooth pavement makes sense from an agency and a user perspective. It's what the public wants, and it's what they should have."

For more information on FHWA's pavement smoothness initiative or obtaining the new pavement smoothness publications, contact Mark Swanlund, 202-366-1323 (email: mark.swanlund@fhwa.dot.gov), or visit FHWA's pavement smoothness Web site at www.fhwa.dot.gov/pavement/pshome.htm.

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