Empirical Assessment of a Markovian Traffic Flow Model

1997 ◽  
Vol 1591 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Chang-Jen Lan ◽  
Gary A. Davis
Keyword(s):  
Traffic Flow ◽  
Traffic Control ◽  
Field Data ◽  
High Order ◽  
Flow Dynamics ◽  
Model Parameters ◽  
Flow Models ◽  
Real Time Traffic ◽  
Flow Parameters ◽  
Traffic Flow Models

Previous research efforts on developing traffic flow models to account for traffic flow dynamics over transportation networks have centered on macroscopic high-order models. It is unclear whether traffic flow dynamics can be well described using a high-order model formulation, but for real-time traffic control, it is important to have tractable yet accurate models. Described here is a set of tractable traffic flow models based on the Markovian compartment concept. The basic models can be further modified to produce effects analogous to high-order models in capturing unstable traffic behavior during congestion. Special treatments are also made to account for the effects of conflicting flow on the predicted turning exit flow at intersection approaches. The proposed models are evaluated using field data. The results indicate that all the model parameters, including traffic flow parameters and gap acceptance parameters, are reasonably estimated, and the underlying models provide good fits to the field data.

scholarly journals Comparison of Traffic Flow Models with Real Traffic Data Based on a Quantitative Assessment

2021 ◽  
Vol 11 (21) ◽  
pp. 9914
Author(s):  
Aleksandra Romanowska ◽  
Kazimierz Jamroz
Keyword(s):  
Traffic Flow ◽  
Deterministic Model ◽  
Empirical Relationship ◽  
Flow Speed ◽  
Traffic Data ◽  
Flow Models ◽  
Flow Parameters ◽  
Fundamental Relationship ◽  
Traffic Flow Models ◽  
Real Traffic

The fundamental relationship of traffic flow and bivariate relations between speed and flow, speed and density, and flow and density are of great importance in transportation engineering. Fundamental relationship models may be applied to assess and forecast traffic conditions at uninterrupted traffic flow facilities. The objective of the article was to analyze and compare existing models of the fundamental relationship. To that end, we proposed a universal and quantitative method for assessing models of the fundamental relationship based on real traffic data from a Polish expressway. The proposed methodology seeks to address the problem of finding the best deterministic model to describe the empirical relationship between fundamental traffic flow parameters: average speed, flow, and density based on simple and transparent criteria. Both single and multi-regime models were considered: a total of 17 models. For the given data, the results helped to identify the best performing models that meet the boundary conditions and ensure simplicity, empirical accuracy, and good estimation of traffic flow parameters.

A SECTION APPROACH TO A TRAFFIC FLOW MODEL ON NETWORKS

2013 ◽  
Vol 24 (05) ◽  
pp. 1350018 ◽  
Author(s):  
ARVIND KUMAR GUPTA
Keyword(s):  
Traffic Flow ◽  
Road Networks ◽  
Simulated Data ◽  
Simplified Approach ◽  
Flow Models ◽  
Special Boundary Condition ◽  
Real Time Traffic ◽  
Traffic Flow Models ◽  
Section Model ◽  
And Control

The development of real time traffic flow models for urban road networks is of paramount importance for the purposes of optimizing and control of traffic flow. Motivated by the modeling of road networks in last decade, this paper proposes a different and simplified approach, known as section approach to model road networks in the framework of macroscopic traffic flow models. For evaluation of the traffic states on a single road, an anisotropic continuum GK-model developed by [Gupta and Katiyar, J. Phys. A38, 4069 (2005)] is used as a single-section model. This model is applied to a two-section single lane road with points of entry and exits. In place of modeling the effect of off- and on-ramps in the continuity equation, a set of special boundary condition is taken into account to treat the points of entry and exit. A four-section road network comprised of two one-lane roads is also modeled using this methodology. The performances of the section approaches are investigated and obtained results are demonstrated over simulated data for different boundary conditions.

Stochastic Traffic Flow Models of the National Airspace System

2008 ◽  
Author(s):  
Monish Tandale ◽  
Jinwhan Kim ◽  
Karthik Palaniappan ◽  
P. K. Menon ◽  
Jay Rosenberger ◽  
...  
Keyword(s):  
Traffic Flow ◽  
National Airspace System ◽  
Flow Models ◽  
Traffic Flow Models

Study of the Response of PW Traffic Flow Model to a Bottleneck on a Circular Road and its Suitability for Heterogeneous Traffic Conditions

2021 ◽  
Vol 9 (4) ◽  
pp. 460-463
Keyword(s):  
Fluid Flow ◽  
Traffic Flow ◽  
Flow Model ◽  
Equation Model ◽  
Heterogeneous Traffic ◽  
Flow Conditions ◽  
Flow Models ◽  
Traffic Conditions ◽  
Model Response ◽  
Traffic Flow Models

The traffic flow conditions in developing countries are predominantly heterogeneous. The early developed traffic flow models have been derived from fluid flow to capture the behavior of the traffic. The very first two-equation model derived from fluid flow is known as the Payne-Whitham or PW Model. Along with the traffic flow, this model also captures the traffic acceleration. However, the PW model adopts a constant driver behavior which cannot be ignored, especially in the situation of heterogeneous traffic.This research focuses on testing the PW model and its suitability for heterogeneous traffic conditions by observing the model response to a bottleneck on a circular road. The PW model is mathematically approximated using the Roe Decomposition and then the performance of the model is observed using simulations.

Dual EKF State and Parameter Estimation in Multi-Class First-Order Traffic Flow Models

2008 ◽  
Vol 41 (2) ◽  
pp. 14078-14083 ◽  
Author(s):  
J.W.C. Van Lint ◽  
Serge P. Hoogendoorn ◽  
A. Hegyi
Keyword(s):  
Parameter Estimation ◽  
Traffic Flow ◽  
Flow Models ◽  
First Order ◽  
Traffic Flow Models

scholarly journals Developing a New Spatial Unit for Macroscopic Safety Evaluation Based on Traffic Density Homogeneity

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chen Wang ◽  
Lin Liu ◽  
Chengcheng Xu
Keyword(s):  
Traffic Flow ◽  
Traffic Control ◽  
Flow Characteristics ◽  
Traffic Density ◽  
Minimization Method ◽  
Spatial Unit ◽  
Flow Parameters ◽  
Safety Knowledge ◽  
Traffic Operation ◽  
Crash Modeling

Macrolevel crash modeling has been extensively applied to investigate the safety effects of demographic, socioeconomic, and land use factors, in order to add safety knowledge into traffic planning and policy-making. In recent years, with the increasing attention to regional traffic management and control, the safety effects of macrolevel traffic flow parameters may also be of interest, in order to provide useful safety knowledge for regional traffic operation. In this paper, a new spatial unit was developed using a recursive half-cut partitioning procedure based on a normalized cut (NC) minimization method and traffic density homogeneity. Two Bayesian lognormal models with different conditional autoregressive (CAR) priors were applied to examine the safety effects of traffic flow characteristics at the NC level. It was found that safety effects of traffic flow exist at such macrolevel, indicating the necessity of considering safety for regional traffic control and management. Furthermore, traffic flow effects were also examined for another two spatial units: Traffic Analysis Zone (TAZ) and Census Tract (CT). It was found that ecological fallacy and atomic fallacy could exist without considering traffic flow parameters at those planning-based levels. In general, safety needs to be considered for regional traffic operation and the effects of traffic flow need to be considered for spatial crash modeling at various spatial levels.

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