Pavement performance models are the main element in any Pavement Maintenance Management System (PMMS). The objectives of this paper are to investigate the factors that affect the pavement condition of the Riyadh street network, to develop pavement performance models, and to validate the developed models. The urban distress index (UDI) was used as a measure of pavement condition. The factors included in the models were pavement age, traffic level, availability of drainage system, and maintenance type. A separate model was developed for pavement sections with utility cut patching. All the developed models were found statistically significant in predicting pavement condition at the 95 percent confidence level.

Pavement weathering or stripping is a major distress in highway networks in arid regions. Using the Saudi Arabian road network as a case study area, seventeen road test sections were selected, out of which eight were stripped and nine were non-stripped. Aggregates from quarries used to build these sections were also collected and subjected to detailed physical and chemical tests to evaluate the ability of these tests to distinguish between stripped and non-stripped sections. The modified Lottman test was used to distinguish between compacted mixes. In addition, the Swedish Rolling Bottle test, was also found to be effective in being able to distinguish between different asphalt-aggregates for stripping potential. Eleven anti-stripping liquid additives, lime and cement, in addition to two polymers, were evaluated for their ability to reduce/eliminate stripping potential of stripping-prone aggregates. It was found that EE-2 Polymer, Portland cement, and their combination were effective with all aggregate sources.