U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-SA-98-022
Date: May 1998
Highway agencies' decisions on when and where to conduct maintenance and rehabilitation work are only as good as the pavement performance models that help them make those decisions. Europe's PARIS (Performance Analysis of Road Infrastructure) project is developing accurate pavement performance models that will give highway agencies the tools to more efficiently plan and schedule maintenance and thereby keep roads in top condition. The project is using data collected from European test sections based on long-term pavement performance (LTPP) program guidelines.
Performance models are critical to the pavement management systems that highway agencies use to plan their strategies for keeping pavements in good shape. By predicting how pavements will deteriorate as they are exposed to climate and traffic, the models help highway agencies determine which pavements require maintenance or rehabilitation, which treatments to use, and when to apply the treatments.
The PARIS project is developing performance models for four types of distress in asphalt pavements: cracking, rutting, raveling, and roughness. These types of distress were chosen because they have a direct effect on the long-term performance of a pavement and on related maintenance and rehabilitation decisions. In addition, these types of distress can be accurately predicted with mathematical models.
Funding for the PARIS project is provided by the European Commission and the 15 participating countries. The project is a follow-on to a study completed last year of the pavement performance models in use in Europe.* That study found that some of the models were outdated and that countries were using models that had not been validated for local conditions. The study recommended a pan-European project that would prevent duplication of effort, allow participants to pool their resources, and produce pavement performance models that would work for pavements anywhere in Europe.
To develop the new pavement performance models, the PARIS project is using data from two sources: 44 accelerated loading test sections and more than 900 in-service pavement test sections. In-service test sections provide the most important information-namely, how real pavements perform under real climate and traffic conditions.
Many of the countries participating in the PARIS project began monitoring in-service pavement test sections several years ago as part of the LTPP program, which was then part of the Strategic Highway Research Program (SHRP). Other test sections were started before the LTPP program began.
"The PARIS project basically is a combination into a single project of all the European LTPP studies that were initiated or in progress in the SHRP days," says Govert Sweere of the Dutch Strategic Highway Research Program (SHRP-NL), who is coordinator of the PARIS project.
European nations were involved with the LTPP program from its beginning. They modeled their own research projects on the North American LTPP program, and they sent staff members to work in the SHRP offices. European nations continue to be involved in the LTPP program, says Charlie Churilla of the Federal Highway Administration's (FHWA) pavement performance division, which oversees the LTPP program. For example, a group known as the international LTPP coordinators meets at the Transportation Research Board (TRB) meeting every year to discuss the LTPP program. European highway agencies and research organizations also provide input to the LTPP program through their representatives on the TRB-LTPP Committee and other groups.
For more information on the PARIS project, contact Govert Sweere at SHRP-NL (phone: 31-15-2518380; fax: 31-15-2518555; email: firstname.lastname@example.org) or visit the PARIS Web site (www.zag.si/paris).
For more information on the LTPP program, contact Charlie Churilla at FHWA (phone: 703-285-2355; fax: 703-285-2767; email: email@example.com).
*COST (Cooperation in Scientific and Technical Research) Study 324,"Long Term Performance of Road Pavement."
The PARIS project is being conducted by transportation research institutes and other organizations in 15 countries.