U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-SA-96-014
Date: March 1996
Making long-term pavement performance (LTPP) products easier to use and more accessible to highway agencies was the focus of the Pavement Performance Advisory Committee (PPAC) meeting held recently in Irvine, California.
PPAC members discussed the status of the general pavement studies (GPS) and specific pavement studies (SPS) being conducted as part of the LTPP project. This spring, an FHWA contractor will examine GPS test sections and data and make recommendations on them, such as altering the frequency of monitoring or dropping certain sections. The contractor's recommendations will be presented at the next PPAC meeting, scheduled for June 1996.
Charlie Churilla, chief of FHWA's Pavement Performance Division, noted that data collection from SPS sites remains a challenge and that the LTPP program needs to develop an updated plan with more specific guidelines for collecting traffic data. To assist States in processing traffic data, PPAC members recommended that FHWA develop and distribute software for this purpose.
To get a better handle on what highway agencies want the LTPP program to deliver, Churilla had visited selected States to hear firsthand the chief engineers' views and expectations of LTPP products. The interviews confirmed that the highway agencies are interested in results, not plans or briefings. They want to know what works and how to detect trends. The results of the survey will be used in refining the LTPP data analysis plan.
FHWA has proposed that an expert task group (ETG) be established to focus on LTPP data analysis. The group would help set priorities, develop tasks, review progress, and evaluate deliverables. The objective is to generate results to meet the needs stressed by the chief engineers and support development of an updated American Association of State Highway and Transportation Officials (AASHTO) design procedure.
The group also discussed the recent relocation of the National Information Management System (NIMS) to an FHWA contractor (Science Applications International Corporation). The move was made to improve the efficiency of NIMS by putting data administration and data access under one organization. Guidelines for data access, processing, and data flow remain the same. The data will continue to undergo the same level of quality-control checks.
FHWA's Monte Symons updated the group on FHWA's proposal to add computed quantities to NIMS. He noted that adding the computed quantities will offer additional insight and eliminate computational redundancy costs, but they will also add complexity to an already large and complex database and will require additional operational resources. In response to PPAC's earlier recommendation, FHWA has created an ETG to help develop this plan and decide what to include and how to calculate the data.
Next, staff from the Transportation Research Board (TRB) offered the recommendation that the PPAC be made smaller and that it have stronger State representation. The restructured committee would have direct access to FHWA and, when appropriate, to AASHTO. Its chairman would be a senior manager from a State department of transportation, and a majority of its members would come from State departments of transportation. The committee would also rely more heavily on ETGs for guidance and review. The PPAC members endorsed TRB's recommendation.
The PPAC members then recommended that the existing ETGs on deflection testing and backcalculation, equipment evaluation, in situ instrumentation, program metrication, and resilient modulus testing proficiency be discharged, with the committee's thanks. The data analysis ETG and a traffic data collection ETG will be the first new committees to be established.
For more information contact Charlie Churilla at FHWA (telephone: 703-285-2355; fax: 703-285-2767) or Robert Raab at TRB (telephone: 202-334-1430; fax: 202-334-3471).