الفهرس 
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Abstract
It is important to realize that the primary function of a highway is to provide a transportation service. In an engineering context this service is measured in terms of the highway ability to accommodate vehicle traffic safety and with some acceptable level of performance (i.e. providing acceptable vehicle speed). In light of this, it is important for the analysis of traffic to begin with consistent techniques that can be used to classify the highways functionally. Many methods are utilized in the study and analysis of capacity and levels of service. Such methods are already established for most of developed countries such as the United States, the United Kingdom and Japan long time ago. There is a strong need for check studies of highway capacity in the developing countries for both divided and undivided regional highways. This research devoted to estimate practical capacity and levels of service for regional highways on Dakahlia governorate. The highway capacity manual method have been used for practical capacity estimation on divided and undivided highways. where links operate under free flow condition. The method is used with some additions to be convenient with this search conditions. The following factors are considered in practical capacity estimation : 1-Roadway characteristics 2-Traffic characteristics 3-Environmental characteristics Roadway characteristics include the physical features incorporated in the design such as: lane width, shoulder width, lateral clearance, radius of horizontal curve and pavement condition Traffic characteristics are influenced by the composition, the habits and desires of the traffic which uses a specified highway. Traffic characteristics considered in this research include: traffic volume, traffic speed, peak hour factor, traffic composition and directional distribution. Land use surrounding the divided regional highways affect on practical capacity such as waterway, agricultural area, adjacent villages or cities are important factors affect on practical capacity in this research. In order to achieve the study objectives, a number of sites on Dakahlia governorate regional highways links and its connection with the surrounding governorates have been selected, these links have permanent or temporary automatic traffic counts from 1992. An experimental program was designed using a video camera to record the existing characteristics and carried out at the selected links and approaches on divided highways. And at links and horizontal curves on undivided highways under study. These data are required for adjustment factors and practical capacity estimation. The data obtained were in the form of, speed of vehicles, traffic volumes and characteristics in the peak hour. Also data include the highway geometry, pavement condition and the surrounding land use. The adjustment factors for practical capacity estimation were estimated and analyzed separately on the links under study. A relationships have been deduced for the estimation of the effect of the adjacent land use on divided highways and the effect of horizontal curves on undivided highways. The relationships have been applied on the selected divided and undivided sites. The effect of pavement condition was estimated on both divided and undivided regional highways under study using the pavement condition rating method. A computer program was built by visual basic language for traffic volume forecasting ( using time series analysis) at target year (2013) based on the annual average daily traffic volumes collected automatically from 1992 to 1998. The data of population and vehicles registration growth are important factors affect traffic forecasting. Levels of service (v/c ratios) have been estimated for each link and proposals for improving levels of service have been discussed. The final results of the search indicate that: 1-Their is a great effect of traffic composition on practical capacity of both divided and undivided regional highways under study. 2-The adjacent land use affect on practical capacity of divided regional highways . 3-Practical capacity decreases only approaching villages and cities due to a great number of heavy and slow vehicles, the existence of pedestrians and lower average speeds. 4-The radius of horizontal curves affect passively on practical capacity of undivided regional highways. 5-Practical capacity more decreases where the radius of horizontal curves decreases, due to the effect of no passing sight distance and lower average speed. 6-Levels of service as measured by (v/c ratios) will increase due to the increase of travel demand. In the future travel demand will increase based on the predicted increase of economic and agricultural activities and the growth of population and car ownership.