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Infrastructure Materials Group

Pavement Smoothness

In the recent National Quality Initiative (NQI) survey pavement smoothness is listed as the most significant measure that the traveling public uses to judge the quality of pavements. Because smoothness is the public’s measure of quality workmanship, FHWA is looking into how to fully understand how to measure it, construct it, and maintain it. So to do this effectively, FHWA is working closely with industry, academia, and state highway agencies (SHA) to:

  1. Identify construction practices that will improve pavement smoothness,
  2. Determine the most efficient, timely, and accurate ways to measure pavement smoothness, and
  3. Develop draft guide specifications and procedures to ensure pavement smoothness and widely disseminate this information to all parties involved in the construction and maintenance of pavements.
One of the most rapidly evolving components in the pursuit of smoother pavements is the equipment used to measure it. The California profilograph (developed by Francis Hveem in 1960) is the most recognizable, and the most commonly used equipment for measuring pavement smoothness today. However, the Industry is currently changing to the use of direct profiling equipment. The direct profiling equipment can efficiently collect actual profile data that is repeatable. The process of data collection and analysis is fully automated. The output from this process can accurately reflect measures of pavement smoothness that relates to drivers comfort and pavement life expectancy. While there are currently many dedicated individuals and groups working to improve the construction and measurement of smoother pavements in this country, the FHWA can play an important role in demonstrating leadership; facilitating and focusing improvements and standardization; and draft guide specifications. By working with groups such as Road Profilers Users Group (RPUG), AASHTO, ACPA, NAPA, and equipment manufactures, FHWA can help to accelerate the use of advanced technology in profile measuring equipment and facilitate implementations of common standards and acceptance criteria for improved construction quality control and accelerated acceptance testing. In order to facilitate standardization and improvements FHWA proposed the following activities:

  1. Assemble an Expert Task Group (ETG) that will identify issues to be addressed; provide technical and administrative reviews; facilitate development, test and evaluation of products and procedures; and help to build implementation consensus,
  2. Gather available information on the state-of-the-practice regarding construction and measurement of smoother pavements.
  3. Field test, evaluate and document capabilities of selected non-contract smoothness measuring devices to demonstrate the usefulness of these devices for both construction quality control and acceptance testing,
  4. Develop a technical guide, based predominately on recent studies, that would include information on the costs to construct smoother pavements, the cost-benefits of smoother pavements, and the most appropriate methods to measure smoother pavements, and
  5. Implementation recommendations, as an information deployment stage, will be made by ETG and SHA participants.

This project is managed by FHWA’s Office of Engineering, Mr. George Jones from the Construction and Maintenance Group, and Mr. Mark Swanlund from the Pavement Division. As of today activity one is completed and two is underway. The other three activities will follow later. Funding will be provided by the office of Technology Applications.

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United States Department of Transportation - Federal Highway Administration