الفهرس | Only 14 pages are availabe for public view |
Abstract Surface conditions of the roadway have an influence on traffic safety, operating speed, maneuverability, driver comfort, and service volume. Although many researchers have studied the impact of many roadway characteristics on traffic stream characteristics and performance, little research has been done to investigate the impact of pavement condition on traffic stream characteristics. Also, the procedures used by Highway Capacity Manual (HCM) to calculate the level-of-service and traffic performance do not include the riding quality of a road (pavement condition). Therefore the overall aim of this work is to study the impact of pavement condition on traffic stream characteristics with specific reference to speed characteristics. Data were collected from 13 sites from rural two-lane, two-way roads in Menoufia and Gharbya Governorates. Each site is consisted of two sections (distressed and un-distressed). Road geometry and pavement condition characteristics were collected manually in the field. Traffic surveys were carried out using automatic traffic counters. The survey placed two automatic traffic counters, at each site, at the two sections, for at least 6 hours. The preliminary analysis indicates that the pavement condition has a pronounced influence on vehicle speed and consequently on traffic operational performance. Additionally, inspections of the standard deviations of speeds for distressed and un-disserted sections show that significant differences occurred mainly in distressed sections. The corollary of this is that greater uniformity of speeds can be expected at good pavement conditions. Moreover, the analysis shows that the traffic flow relationships for distressed and un-distressed road sections are different, under the same traffic conditions, especially at lower PCI values. These relationships are going to be similar in the case of good pavement condition (higher PCI values). |