T I Al-Suleiman

Prediction of Pavement Remaining Service Life Using Roughness Data—Case Study in Dubai

This paper presents a methodology for predicting Pavement Remaining Service Life (RSL) using roughness data in terms of the International Roughness Index (IRI). The serviceability, roughness and age data pertaining to more than 400 sections of asphalt-surfaced pavements in Dubai Emirate, U.A.E. were collected and analysed. Models for estimating the Present Serviceability Index (PSI) based on direct roughness measurements were developed and compared with the results of similar international studies. Separate regression models for both heavily trafficked lane (slow lane) and fast traffic lane are presented. The developed roughness—serviceability and roughness—age models were found statistically significant and predictable. A reliable time approach for estimating the RSL for both lanes based on the current age of the pavement has been used. The developed RSL models were found very helpful in facilitating the decision making regarding maintenance, rehabilitation and the efficient use of the allocated maintenance budget.

AN EVALUATION OF EFFECTS OF ROUTINE MAINTENANCE ON HIGHWAY PAVEMENT SURFACE CONDITION. INFORMATIONAL REPORT

This research was undertaken to analyze the effects of routine maintenance expenditure level on pavement surface condition and consequently on pavement service life. A conceptual framework for assessing the relationship between pavement age and routine maintenance expenditure level was developed. Surface roughness was used as a measure of pavement condition and pavement age at terminal roughness value was considered as a measure of pavement service life. The effects of traffic loading and regional factors were also considered in the framework. The major work items within the scope of study included: (i) the development of mathematical models for routine maintenance and regional effects; (ii) the evaluation of the effects of pavement age and traffic loading on maintenance effectiveness; (iii) the examination of the relationship between routine maintenance and pavement service life; and (iv) the study of the impacts of routine maintenance on timing of pavement resurfacing. An integrated data base was developed from selected pavement sections from the Indiana state highway system including information on pavement routine maintenance, pavement roughness, and pavement characteristics. The data were collected based on pavement contract sections. The results indicated that deterioration in pavement surface condition in the northern region was higher than that in the southern region. However, maintenance effectiveness was found, in general, higher in the northern region. Also, the effectiveness of patching and joint and crack sealing was found higher than that of patching alone. In addition, maintenance effectiveness for pavements that are in the middle range of their service life was found higher than that for pavements that are in the early phase of their service life. Multiple regression was used to develop predicion models for the effects of routine maintenance expenditure level on pavement service life. The results of these models indicated that if patching and crack sealing expenditure level increases from low to high levels, resurfacing can be postponed 1 to 3.3 years for overlaid pavements and 1.6 to 8 years for flexible pavements.

Effect Of Traffic Volume On Air Pollution In Urban Areas - Case Study In Jordan

This paper presents an evaluation and modelling of air pollution in urban areas. To achieve the objective of this paper, eighteen major sites (eight signalized intersections and ten main rotaries) were selected in Irbid City-Jordan and taken as a case study. The traffic counts at these sites were performed during peak and off-peak hours taking into consideration the seasonal variations. Special technical equipment were used to measure the concentration of the following air pollutants : Carbon Monoxide (CO) , Sulfur Dioxide (SO.) , Nitrogen Oxides (NOx) , and particulate. The results showed that the effect of volume of Gasoline-Powered Vehicles on CO, NOx and particulate were statistically significant. While, the SO^ was found more correlated with the volume of Diesel-Powered Vehicles. In general, the predicted levels of air pollution at the signalized intersections were found higher than those at the rotaries .