U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-RD-99-106
Date: August 1999
After simulating more than 10 years of Interstate-level traffic loads in 2.5 years, the driverless trucks at the WesTrack pavement testing facility near Reno, Nevada, have finished their runs. Guided by wires buried in the hot-mix asphalt (HMA) pavement, the four heavily ladentrucks traveled an average of 15 hours a day around the 2.9-km (1.8-mi) oval test track. Their travels were designed to evaluate how variations in HMA construction quality, such as asphalt content, aggregate gradation, and compaction, affect pavement performance and to validate the Superpave mix design and analysis procedures. By evaluating these variations, researchers could advance the development of performance-related specifications for HMA construction. Ultimately, these specifications will help improve pavement performance.
Over the past 2 years, the Indiana Department of Transportation (DOT) has been tracking the field performance of its Superpave pavements, measuring friction, roughness, rut depth, and pavement condition. The DOT randomly selected 14 Interstate projects, with half designed with the Marshall procedures and half with the Superpave system. The 1997 data indicate that the Superpave pavements have higher friction and pavement condition ratings than do the Marshall mixes. There are no significant differences in rutting or roughness. Results from 1998 are still being compiled, but preliminary data show similar performance trends. The performance tracking is expected to continue for the next 10-12 years. For more information, contact Richard Smutzer at Indiana DOT, 317-232-5280, x204 (fax: 317-356-9351; email: firstname.lastname@example.org).
The long-term pavement performance (LTPP) program took its training on the use of the DataPave software abroad last month, hosting a 1-day workshop in Cairo, Egypt. Brought to Egypt at the request of Essam Sharafi, a professor at Cairo University, the workshop focused on how to use the software's different modules to obtain data on everything from traffic to environmental conditions at the more than 2,400 LTPP test sections on in-service highways and roads across the United States and Canada.
Representatives from five States, contracting and consulting firms, and the Federal Highway Administration (FHWA) gathered in St. Louis in May for the kick-off meeting of the National Quality Initiative (NQI) Lead States team. Believing that "highways are this Nation's most important infrastructure and that we need better quality highway work," as NQI Administrator Bob Templeton noted, the goal of the Lead States team is to motivate other States and their partners to implement NQI programs in order to improve performance in building and maintaining roads.
When a State department of transportation (DOT) embarks on a new construction or rehabilitation project, it usually relies not only on its own staff to sample and test the materials used in construction, but also on personnel working for various contractors. In an era of continually changing technologies and advances in knowledge, DOTs are looking for assurance that these technicians, whether they are State employees or contractors, are up to speed on the latest methods and specifications. In response, some States have started regional programs to test workers and to certify those who meet a basic set of standards.
A new, broad-based committee established by the Transportation Research Board (TRB) will provide guidance to, and oversight of, a new program of concrete pavement research. The Committee for Research on Improved Concrete Pavement for Federal-Aid Highways was formed as a result of the Transportation Equity Act for the 21st Century (TEA-21), which authorized a 6-year program "to carry out research on improved methods of using concrete pavement in the construction, reconstruction, and repair of Federal-aid Highways."