There is little doubt that those of us who are involved in the great industry of motor vehicle transportation—whether it be along the lines of design, maintenance, or operations—have come to recognize that street and highway capacity considerations are indispensable. It is unfortunate, however, that too often there is a lack of clear understanding of what we mean by capacity and how it actually...

Hypotheses and some results of the three-phase traffic theory by the author are compared with results of the fundamental diagram approach to traffic flow theory. A critical discussion of model results about congested pattern features which have been derived within the fundamental diagram approach to traffic flow theory and modelling is made. The empirical basis of the three-phase traffic theory...

The urban weaving sections are more complex due to the various disturbing elements within section, such as lane-change situations. These turbulences reduced road capacity and increased vehicle exhaust emissions. Highway Capacity Manual (HCM 2010) has a methodology for analysis of free highways; roads is not investigated in HCM. Therefore, main objective this research present systematic factors ...

Transportation assume no liability for the contents or use thereof. The contents do not necessarily reflect the official views or policies of the State of California or the Department of Transportation. This report does not constitute a standard, specification, or regulation. 2 Abstract In this report we present a methodology to decide capacity expansions for a transportation network that finds...

The importance of increments to an existing highway system depends upon the values they add to the pre-existing network. Over 50 years ago, Mohring [1965] suggested this logic for planning optimal highway investment programs. Moreover he argued it could be implemented by measuring the quasi-rents generated by specific additions to an existing roadway system. To our knowledge no one has managed ...

Highway Capacity Manual 2010 provides various factors to adjust the base saturation flow rate for the capacity analysis of signalized intersections. No factors, however, is considered for the potential change of signalized intersections capacity caused by the access point closeing to the signalized intersection. This paper presented a theoretical model to estimate the lane group capacity at sig...

Calibration is a conventional method which is utilized to adapt traffic models based on local situations in order to achieve best results. One of the issues regarding the efficiency of this method is whether traffic models should be calibrated only in one or two major cities of a country or calibrated based upon a comprehensive selection of cities. Therefore, this study, which has used the actu...

Accurate estimation of saturation flow rate is a prerequisite for accurate estimation of level of service and delays of signalized intersections. Saturation flow rate of intersections depends on many factors, including traffic behavior and culture. One of the important problems of traffic behavior in Iran is the violation of law at the physical region of intersections. The main purpose of this ...

The core methodology of the Highway Capacity Manual (HCM) 2010 for freeway analyses is based on Free-Flow Speed (FFS). Moreover, weaving segments are major elements of freeway facilities that form where two one-way traffic streams intersect by merging and diverging maneuvers. Hence, this study used three different methods to compute FFS of a ramp-weaving segment, and then employed the proposed ...