One of the goals of local transportation agencies is to improve the quality of life for citizens and visitors by ensuring the efficient and safe movement of people and goods through the roadway system. Maintenance and rehabilitation of pavements are necessary to ensure that roadway networks continue to perform at their optimum. Currently, maintenance and rehabilitation of roadway networks depend on several factors including pavement condition indices, funding availability, among others. Previous studies have established relationships between crash frequency and pavement condition indices. However, the combined influence of speed, volume, and crash frequency on pavement indices, and thereby pavement management efforts has not been thoroughly examined. In this paper, a multinomial logistic regression was employed for 193 arterial segments to establish a new categorical variable: Composite Safety Index (CSI). The CSI values or ratings were based on pavement indices, crash frequency, traffic volumes and vehicular speeds to help categorize pavement sections for either maintenance or rehabilitation. The results indicated that the selected independent variables were statistically reliable in ranking pavement sections for rehabilitation or maintenance based on their CSI values.

This study focused on determining the prevailing Saturation Flow Rate (SFR) for specific lane groups in an urban area: District of Columbia (DC). The lane groups considered were Through (T), shared Through and Right (TR), shared Through and Left (TL), and exclusive Left turn (L) lane groups. These SFR values could then be used to calculate the local base SFR. The study determined the prevailing SFR for these lane groups based on data collected at 81 intersections. The hypothesis that the mean SFRs for all the lane groups are different was tested at a 5% level of significance. From the results, the mean prevailing SFR for the T, TR, TL and L lane groups were 1,559, 1,461, 1,566 and 1,460 vphpl respectively. Those prevailing SFRs can be used for planning analyses in the District of Columbia. The results also indicated that these mean prevailing SFRs are statistically similar at 95% confidence interval. Based on the results, a local base SFR for the City can be determined for each lane group.