الفهرس 
CHAPTER ONE: INTRODUCTionOnly 14 pages are availabe for public view
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Abstract
Vehicle delay is considered the most important measure of effectiveness (MOE) at signalized intersections because it is used in the estimation of level-of-service (LOS) and intersection characteristics. In addition, it is used for evaluating the performance of an intersection under different control, demanding and operating conditions. Although many researchers have studied the control delay estimation at signalized intersections in several studies, it seems that no research has been done in Egypt. Therefore the overall aim of this work is to develop models to analyze and estimate the delay times at signalized intersections in Egypt. To achieve this goal, Global Positioning System (GPS) device is used. The GPS device provides an opportunity to accurately measure intersection delay, which is composed of deceleration delay, stopped delay, and acceleration delay. This device is used for identifying critical points along the intersection by using the speed and acceleration profiles associated with each delay component based on one second time intervals. Speed profiles are used for the identification of stopped time periods, and acceleration profiles are used for detecting deceleration onset points and acceleration ending points. Using GPS device, a pilot survey was executed on two signalized intersections in order to make sure that the device gives the correct trendline for speed and acceleration profiles. After checking, the formal survey was performed and 51 runs for the through traffic were conducted at a T-signalized intersection. Geometric data and signal data were collected manually in the field. Also, traffic data were collected manually by observers recorded the number of vehicles for each existing movement at all intersection approaches. Traffic counts were performed from 6.00 a.m. to 9.00 a.m. for every 5-minute intervals. The preliminary analysis indicated that the average control delay of non-stopped vehicles is small, and it is about 17% and 23% of the overall value of control delay at peak and off peak hours respectively. Additionally, the total stopped delay for the sampled runs comprises about 50% of the resulted control delay. Moreover,
the analysis showed that deceleration delays tend to be larger than acceleration delays for non-stopped vehicles and vice versa for stopped vehicles. To model the relationships between the delay components, a regression analysis was performed (control delay as dependent variable and deceleration, stopped, and acceleration delays as independent variables). from the analysis, it was found that the developed models are significant at 95% confidence level as the significance of F statistic >0.001. Furthermore, the stopped time component is considered the most influential independent variable on the estimation of control delay and has the most contribution in all models. A comparison between the current study and previous studies in the literature was performed. Such comparison revealed that the estimated control delay in the current study is consistent with the previous studies. SIDRA and VISSIM software were used to estimate the theoretical delay time which was compared with the field results. The outputs indicated that the developed model at peak hour needed parameter calibration. This is because; absolute error- which is used as the evaluation criterion and can be calculated by the difference between the observed and predicted delays- is not within certain limits. VISSIM software was used to perform the calibration process. This calibration is followed by the validation of this model using data from different time period resulting in the validity of using the model at signalized intersections that have similar characteristics of the area under study. Also, the effect of traffic volume and lane width parameters on the simulated control delay was studied and it was found that there is a direct proportion with traffic volume parameter and an inverse proportion with lane width parameter. Traffic engineers can use the delay obtained from the developed models to estimate the intersection LOS value which in turn provides a basis for making decisions concerning geometric designs and signal operations. Also, they should consider the delay minimization as a primary optimization criterion when determining the operating parameters of traffic signals at isolated intersections. Moreover, to improve the overall flow of traffic on the routes, lane width should not be less than 11 ft and the traffic volumes should not exceed 900 veh/h.