Optimal Design of an Isolated Signalized Intersection with Double Stop Lines for Mixed Traffic

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.

Download Full-text

Saturation Flow Model for Signalized Intersection under Mixed Traffic Condition

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118777407 ◽

2018 ◽

Vol 2672 (15) ◽

pp. 55-65 ◽

Cited By ~ 7

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.

Download Full-text

Mixed-traffic signal timing at signalized intersection based on adaptive co-evolutionary algorithm

2008 7th World Congress on Intelligent Control and Automation ◽

10.1109/wcica.2008.4594309 ◽

2008 ◽

Author(s):

Ming He ◽

Hui Wang

Keyword(s):

Evolutionary Algorithm ◽

Traffic Signal ◽

Signalized Intersection ◽

Signal Timing ◽

Mixed Traffic ◽

Traffic Signal Timing

Download Full-text

PEDESTRIAN SAFETY EVALUATION OF SIGNALIZED INTERSECTIONS USING SURROGATE SAFETY MEASURES

Transport ◽

10.3846/transport.2020.12157 ◽

2020 ◽

Vol 35 (1) ◽

pp. 48-56

Author(s):

Sankaran Marisamynathan ◽

Perumal Vedagiri

Keyword(s):

Safety Evaluation ◽

Pedestrian Safety ◽

Signalized Intersections ◽

Signalized Intersection ◽

Mixed Traffic ◽

Model Framework ◽

Safety Measures ◽

Severity Level ◽

Traffic Conditions ◽

Surrogate Safety Measures

The large proportions of pedestrian fatalities led researchers to make the improvements of pedestrian safety at intersections. Thus, this paper proposes a methodology to evaluate crosswalk safety at signalized intersections using Surrogate Safety Measures (SSM) under mixed traffic conditions. The required pedestrian, traffic, and geometric data were extracted based on the videographic survey conducted at signalized intersections in Mumbai (India). Post Encroachment Time (PET) for each pedestrian were segregated into three categories for estimating pedestrian–vehicle interactions and Cumulative Frequency Distribution (CDF) was plotted to calculate the threshold values for each interaction severity level. The Cumulative Logistic Regression (CLR) model was developed to predict the pedestrian mean PET values in the cross-walk at signalized intersections. The proposed model was validated with a new signalized intersection and the results were shown that the proposed PET ranges and model appropriate for Indian mixed traffic conditions. To assess the suitability of model framework, model transferability was carried out with data collected at signalized intersection in Kolkata (India). Finally, this study can be helpful to rank the severity level of pedestrian safety in the crosswalk and improve the existing facilities at signalized intersections.

Download Full-text

Eco-Speed Guidance for the Mixed Traffic of Electric Vehicles and Internal Combustion Engine Vehicles at an Isolated Signalized Intersection

Sustainability ◽

10.3390/su11205636 ◽

2019 ◽

Vol 11 (20) ◽

pp. 5636 ◽

Cited By ~ 1

Author(s):

Kai Liu ◽

Dong Liu ◽

Cheng Li ◽

Toshiyuki Yamamoto

Keyword(s):

Energy Consumption ◽

Electric Vehicles ◽

Emission Reduction ◽

Combustion Engine ◽

Signalized Intersection ◽

Mixed Traffic ◽

Mixed Traffic Flow ◽

Energy Emissions ◽

The Impact ◽

Guidance Model

Although electric vehicles (EVs) have been regarded as promising to reduce tailpipe emissions and energy consumption, a mixed traffic flow of EVs and internal combustion engine vehicles (ICEVs) makes the energy/emissions reduction objective more difficult because EVs and ICEVs have various general characteristics. This paper proposes a low-emission-oriented speed guidance model to address the energy/emission reduction issue under a mixed traffic flow at an isolated signalized intersection to achieve the objective of reducing emissions and total energy consumption while reducing vehicle delay and travel time. The total energy/emissions under different market penetration rates of EVs with various traffic volumes are analyzed and compared. Numerical examples demonstrate that the proposed speed guidance model has better performance than those without considering the impact of queues. For a certain traffic volume, the energy/emission reduction effects under speed guidance will increase with an increasing share of EVs. This paper also explores the impact of the time interval for guidance renewal on vehicle emissions in practice.

Download Full-text