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Reflective cracking, a common distress that affects composite highway pavements, is caused by cyclical movements of the underlying concrete base that is overlaid with hot-mix-asphalt in reaction to climatic and traffic conditions. A saw and seal method, which involves making saw cuts in the overlaying asphalt, (above the concrete joints) and sealing them with a compressible rubberized low modulus material, was studied for its effectiveness in mitigating reflective cracking in newly constructed pavements in Washington DC. In the 4½ year field study, the widths of the transverse and longitudinal saw-cuts made in the hot-mix-asphalt overlay were measured every three months at 22 saw-cut points. Multiple regression analyses and statistical tests of significance were conducted to determine the statistical relationship between the changes in mean daily air temperature, average daily traffic, pavement age and the variations of the sawcut widths. The interactions of changes in mean daily air temperature and ADT had a statistically significant impact on variations in transverse and longitudinal saw-cut widths, accounting for 95.7% and 91.4% of variations respectively. Pavement age also had a significant impact but was excluded due to multicollinearity with ADT. In conjunction with the statistical analyses, a visual condition comparison with a similar adjacent pavement section built without any saw-cut treatments showed that the saw and seal method effectively controlled reflective cracking in the composite pavement.

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The Federal Highway Administration (FHWA) requires each state in the United States to report the International Roughness Indices (IRI) of their road network in the annual Highway Performance Monitoring System (HPMS). The reported IRI for road segments are compared to the national standards developed by the FHWA based on national data. Deviations from the national standards are used to identify road segments that need to be included in repair or maintenance programs. The FHWA IRI thresholds for all road classes range between 170 in/mi and 96 in/mi for "acceptable" pavements, and 95 in/mi or less for "good" pavements. The use of the IRI for identifying sections of highways for repair and rehabilitation has been under review in several states. There is the concern that the national values of the IRI often do not reflect the ride smoothness perceived by citizens in the specific jurisdictions. This research obtained the ride quality ratings of residents of a dense urban area (Washington, DC) and correlated those with the IRI values for selected road segments. This research presents the IRI thresholds developed for the urban area based on the regression models obtained and the standard IRI thresholds for newly constructed pavement.