scholarly journals FIELD SATURATION FLOW MEASUREMENT USING DYNAMIC PASSENGER CAR UNIT UNDER MIXED TRAFFIC CONDITION

2017 ◽  
Keyword(s):  
Flow Measurement ◽  
Mixed Traffic ◽  
Traffic Condition ◽  
Passenger Car ◽  
Passenger Car Unit ◽  
Saturation Flow

scholarly journals Passenger Car Unit Estimation at Signalized Intersection for Non-lane Based Mixed Traffic Using Microscopic Simulation Model

2017 ◽  
Vol 45 (1) ◽  
pp. 12 ◽  
Author(s):  
Gowri Asaithambi ◽  
Hayjy Sekar Mourie ◽  
Ramaswamy Sivanandan
Keyword(s):  
Simulation Model ◽  
Signalized Intersection ◽  
Accurate Estimation ◽  
Mixed Traffic ◽  
Passenger Car ◽  
Traffic Conditions ◽  
Passenger Car Unit ◽  
Road Width ◽  
On The Road ◽  
Chennai City

In India, traffic on roads is mixed in nature with widely varying static and dynamic characteristics of vehicles. At intersections, vehicles do not follow ordered queue and lane discipline. Different vehicle types occupy different spaces on the road, move at different speeds, and start at different accelerations. The problem of measuring volume of such mixed traffic has been addressed by converting different vehicles categories into equivalent passenger cars and expressing the volume in terms of Passenger Car Unit (PCU) per hour. The accurate estimation of PCU values for different roadway and traffic conditions is essential for better operation and management of roadway facilities. Hence, the objective of the present study is to estimate the PCU values at signalized intersection in mixed traffic and to study the influence of traffic volume, traffic composition and road width on PCU values.For this purpose, a mixed traffic simulation model developed specifically for a signalized intersection was used. The model was calibrated and validated with the traffic data collected from a signalized intersection in Chennai city. Simulation runs were carried out for various combinations of vehicular composition, volume levels and road width. It was observed that presence of heavy vehicles and increase in road width affects the PCU values. The obtained PCU values were statistically checked for accuracy and proven to be satisfied. The PCU values obtained in this study can be used as a guideline for the traffic engineers and practitioners in the design and analysis of signalized intersections where mixed traffic conditions exist.

Saturation Flow Model for Signalized Intersection under Mixed Traffic Condition

2018 ◽  
Vol 2672 (15) ◽  
pp. 55-65 ◽  
Author(s):  
Sabyasachi Biswas ◽  
Souvik Chakraborty ◽  
Indrajit Ghosh ◽  
Satish Chandra
Keyword(s):  
Conventional Method ◽  
Detailed Comparison ◽  
Heterogeneous Traffic ◽  
Signalized Intersection ◽  
Percentage Error ◽  
Mixed Traffic ◽  
Kriging Method ◽  
Traffic Condition ◽  
Saturation Flow ◽  
The Impact

Saturation flow is one of the most important functional parameters at signalized intersections. It is to be noted that saturation flow is a functional measure of the intersection operation, which indicates the probable capacity if working in an ideal situation. However, determination of the saturation flow is a challenging task in developing countries like India where vehicles with diverse static and dynamic characteristics use the same carriageway. At the same time, it is influenced by several other factors. In this context, the present research is carried out to examine the effects of traffic composition, approach width and right-turning movements on saturation flow under heterogeneous traffic conditions. This paper proposes a model for computing saturation flow at the signalized intersection under mixed traffic condition based on Kriging approach. A detailed comparison of the mean saturation flow values obtained by the conventional method, regression method, and Kriging method has also been presented. Low mean absolute percentage error values (<5%) have been obtained for saturation flow by Kriging method with respect to the conventional method. Finally, the proposed models are used to evaluate the impact of right-turning vehicles on saturation flow under shared lane condition.

scholarly journals Measuring Passenger Car Unit (PCU) at Four Legged Roundabout using Time Occupancy Data Collected from Drone

2018 ◽  
Vol 7 (2) ◽  
pp. 77-84 ◽  
Author(s):  
Sugiarto Sugiarto ◽  
Fadhlullah Apriandy ◽  
Ruhdi Faisal ◽  
Sofyan M. Saleh
Keyword(s):  
National Level ◽  
Highway Capacity ◽  
Traffic Condition ◽  
Passenger Car ◽  
Highway Capacity Manual ◽  
Passenger Car Unit ◽  
Aceh Province ◽  
Pass Through ◽  
Time Required ◽  
Traffic Operation

This study aims to measure the values of passenger car unit (PCU) at a four-legged roundabout based on the time occupancy data in complex traffic operation. Within mixed traffic, the PCUs are needed as a equivalency factor to convert various type of vehicles to a standard unit. The unit of PCU was used to determine capacity and level of service of specific the traffic condition. The composition of vehicles going through the intersection,  mostly varies and each type of vehicles tends to have diverse effects on capacity and level of services. Consequently, a conversion factor from various vehicles to a standard vehicle is required.   The data of this study was collected using a drone at the investigated roundabout at one of the major roundabouts in Aceh Besar, Aceh province, Indonesia. The method used was the vehicle's time occupancy, in which  calculated from  the average time required by each vehicle to pass through the roundabout area. The results show that the PCU values obtained is 0.16 for motorcycle, 0.59 for rickshaw, 1.07 for pickup, 1.91 for a medium vehicle, and 3.76 for the heavy vehicle. These results should be utilized for converting various type of vehicles into PCUs to estimate capacity and level of services, especially at the roundabout trafict. This results may be suitable to revise the Indonesian Traffic Code, named Indonesian Highway Capacity Manual 1997, and useful for ongoing national-level efforts to upgrade the  Indonesian Highway Capacity Manual.

Developing Mixed Traffic Equivalency Factors to Estimate Saturation Flow at Urban Signalized Intersections

2021 ◽  
pp. 036119812110186
Author(s):  
Pinakin N. Patel ◽  
Ashish Dhamaniya
Keyword(s):  
Signalized Intersections ◽  
Mixed Traffic ◽  
Heavy Vehicles ◽  
Commercial Vehicles ◽  
Passenger Car ◽  
Flow Rates ◽  
Geometric Conditions ◽  
Metropolitan Cities ◽  
Equivalency Factors ◽  
Saturation Flow

This study proposes a time occupancy approach to estimate passenger car units (PCUs) at urban signalized intersections with different interaction levels between vehicles under saturated green time conditions. The study shows a variation in PCUs with varied traffic and geometric conditions. Traffic data have been collected through videography techniques at signalized intersections in three metropolitan cities in India. Traffic flow discharge and clearance time of different vehicular categories have been extracted from the video during the saturated green time. The observed ranges of dynamic PCU values for two-wheelers, three-wheelers, big cars, light commercial vehicles, and heavy vehicles are 0.12 to 0.32, 0.45 to 0.80, 1.40 to 1.80, 1.60 to 2.20, and 3.50 to 6.50, respectively. Regression-based PCU models have been developed for each vehicle category to address the variation of individual vehicle PCUs with traffic compositions and flow rates. The model analysis shows that traffic compositions and flow rates are significantly affecting the PCU values. The PCU is a complex parameter requiring several field attributes. Therefore, to overcome the complexity of estimating PCUs, a concept of flow equivalency factor (FEF) has been proposed based on the estimated PCUs. The FEF can directly convert the mixed motorized vehicular flow into an equivalent standard passenger car flow without actually making use of different vehicles’ PCU factors. All the developed models have been validated for field conditions and results are found promising with field data. The developed approach can be used effectively for developing countries with a mixed traffic stream.

Equivalency Factor Based on Acceleration Noise for Mixed Traffic Condition

2019 ◽  
Vol 5 (2) ◽  
Author(s):  
S. Salini ◽  
R. Ashalatha ◽  
S. Aswathy Mohan
Keyword(s):  
Mixed Traffic ◽  
Traffic Condition
Sign in / Sign up

Export Citation Format

Share Document