scholarly journals QUEUE DISCHARGE HEADWAY: CHARACTERISTICS, DISTRIBUTIONS AND EFFECTS ON SATURATION FLOW RATES AT SELECTED SIGNALIZED INTERSECTIONS IN LAGOS

2021 ◽  
Vol 12 (1) ◽  
Keyword(s):  
Signalized Intersections ◽  
Flow Rates ◽  
Saturation Flow ◽  
Queue Discharge Headway

scholarly journals Heterogeneous Lanes’ Saturation Flow Rates at Signalized Intersections

2014 ◽  
Vol 138 ◽  
pp. 3-10 ◽  
Author(s):  
Huayan Shang ◽  
Yiming Zhang ◽  
Lang Fan
Keyword(s):  
Signalized Intersections ◽  
Flow Rates ◽  
Saturation Flow

Estimating Intersection Approach Delay Using 1985 and 1994 Highway Capacity Manual Procedures

1996 ◽  
Vol 1555 (1) ◽  
pp. 23-32
Author(s):  
Stephen M. Braun ◽  
John N. Ivan
Keyword(s):  
Field Measurements ◽  
Signalized Intersections ◽  
New Technique ◽  
Adjustment Factor ◽  
Highway Capacity ◽  
Flow Rates ◽  
Left Turn ◽  
Highway Capacity Manual ◽  
A New Technique ◽  
Saturation Flow

The current methods for determining average stopped delay at signalized intersections were studied. Field measurements of average stopped delay were obtained and compared with values computed using both the 1985 and 1994 editions of the Highway Capacity Manual (HCM). The 1994 HCM uses an equation to predict the progression adjustment factor (PF), a new technique for determining the left-turn adjustment factor for saturation flow rates, and a new set of equations for determining the uniform delay parameter for left-turn lane groups with primary and secondary phasing. Overall, the 1994 HCM produces better estimates of intersection stopped delay than the 1985 HCM.

Pedestrian Impedance of Turning-Movement Saturation Flow Rates: Comparison of Simulation, Analytical, and Field Observations

1997 ◽  
Vol 1578 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Nagui M. Rouphail ◽  
Brian S. Eads
Keyword(s):  
United States ◽  
Empirical Data ◽  
The United States ◽  
Signalized Intersections ◽  
Urban Traffic ◽  
Analytical Models ◽  
Flow Rates ◽  
Micro Simulation ◽  
Logarithmic Relationship ◽  
Saturation Flow

TRAF-NETSIM and its successor CORSIM are comprehensive micro-simulation environments that have been widely used to model the urban traffic environment in the United States and abroad. CORSIM is employed in this study to simulate and evaluate the effects of pedestrian flows on right-turn saturation flow rates at signalized intersections. The saturation flow rates returned by CORSIM were compared with field data collected throughout the United States and with three existing analytical models in the United States, Australia, and Canada. These comparisons indicated that CORSIM models pedestrian interference with the turning vehicles more severely than the three analytical methods, but with a smaller effect than the empirical data indicate. Further, the empirical data exhibit a logarithmic relationship between saturation flow rate and opposing pedestrian volume, compared with the linear relationship used in the simulation and analytical models. Implications for the design and analysis of signalized intersections are presented.

scholarly journals Effect of U-Turns and Heavy Vehicles on the Saturation Flow Rates of Left-Turn Lanes at Signalized Intersections

2020 ◽  
Vol 12 (11) ◽  
pp. 4485
Author(s):  
Abdelrahman Abuhijleh ◽  
Charitha Dias ◽  
Wael Alhajyaseen ◽  
Deepti Muley
Keyword(s):  
Flow Rate ◽  
Signalized Intersections ◽  
The State ◽  
Heavy Vehicles ◽  
Flow Rates ◽  
Left Turn ◽  
Highway Capacity Manual ◽  
Adjustment Factors ◽  
Saturation Flow Rate ◽  
Saturation Flow

The Saturation Flow Rate (SFR) is a primary measure that can be used when estimating intersection capacity. Further, the efficiency of signal control parameters also depends on the accuracy of assumed SFR values. Driver behavior, type of movement, vehicle type, intersection layout, and other factors may have a significant impact on the saturation flow rate. Thus, it is expected that driving environments that have heterogeneous driver populations with different driving habits and cultures may have different SFRs. In practice, the proposed SFRs based on US standards (Highway Capacity Manual, 2016) have been adopted in the State of Qatar without validation or calibration to consider the local road environment and the characteristics of the driving population. This study aims to empirically analyze the saturation flow rates for exclusive left-turn lanes and shared left- and U-turn lanes at two signalized intersections in Doha city, while considering the effects of heavy vehicles and U-turn maneuvers. Empirical observations revealed that the average base SFR, i.e., when the influences from heavy vehicles and U-turns were excluded, could vary approximately from 1800 vehicles per hour per lane (vphpl) to 2100 vphpl for exclusive left-turning lanes and approximately from 1800 vphpl to 1900 vphpl for shared left- and U-turning lanes. Furthermore, this study proposed different adjustment factors for heavy vehicle and U-turn percentages which can be applied in practice in designing signalized intersections, particularly in the State of Qatar.

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