The Florida Department of Transportation initiated a field study to assess the feasibility and appropriateness of implementing the use of laser-based high-speed profilers to automate its process of determination of ride acceptance. If a high-speed profiler is to be considered for determination of ride acceptance, it is essential that its level of accuracy and precision be assessed. For such a purpose, profile measurements were acquired by using five profilers concurrently on a large number of asphalt pavement sections. Also, to evaluate the effects of surface texture on these measurements, the test sections were randomly selected to include both open-and dense-graded surface mixtures. The profile data collected were first analyzed to determine the profile indices in terms of the ride number and the international roughness index at each test site. The results were then used as a basis for an evaluation of the repeatability and reproducibility of the profiling units. In addition, the effects of a profiler operating speed gradient as well as those of the pavement surface texture on roughness measurements were assessed.

The Florida Department of Transportation (FDOT) is in the process of evaluating the protocols for collecting and analyzing roughness data. As part of that evaluation, a nationwide survey was performed to identify the trends and practices of various departments of transportation with regard to roughness data collection and analysis. All responding states indicated interest in obtaining the results of the survey, which was mailed to all 50 state departments of transportation. The responses show that most states are using laser-type road profilers for roughness measurements. The international roughness index (IRI) is the most widely used roughness index. Highway Performance Monitoring System (HPMS) data from different states are collected by using different equipment, and the data are collected in various wheelpaths and filtered differently. Stricter guidelines should be developed to ensure the consistency of HPMS data.

Initial pavement smoothness has been shown to improve overall pavement performance. This combined with the need to provide a comfortable ride for the driving public underscores the importance of achieving high initial pavement smoothness. The Florida Department of Transportation has developed smoothness specifications for asphalt pavements. These smoothness specifications will be used on high-speed facilities and will be based on measurements obtained with laser road profilers. The ultimate goal is to include incentive and disincentive specifications aimed at rewarding the contractor for a high-quality ride and simultaneously providing a financial deterrent to providing a poor-quality ride.

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