The SPS experiments were designed to learn how such factors as cumulative traffic loading affect pavements of different compositions, environmental conditions, and layer thicknesses. While the study is targeted to those States with SPS sites, participation by other States is encouraged, given that all States will benefit from the increased understanding of pavement performance that the SPS experiments will provide. The quality of data obtained from WIM sensors, which collect information on such factors as vehicle and axle weights, is highly dependent upon the pavement in which they are installed.
Smoother pavements provide more accurate and less variable measurements.
Once the site visits have been completed, a report will be prepared, providing a baseline for future data analysis and site evaluations. FHWA's LTPP team plans to conduct a series of pilot projects to validate the protocols and train highway personnel in annual WIM evaluation activities.