Modeling

Extracting Vehicle Trojectories from Video Data: The NGSIM Ptototype Data Set

Sim, Z W
Skabardonis, A
University of California, Berkeley
2005

The Next Generation Simulation (NGISM) program, initiated by the Federal Highway Administration (FHWA), has as its objective the development of behavioral algorithms that support microscopic traffic simulation, accompanied by documentation and validation sets. This article relates how algorithms from the California Partners for Advanced Transit and Highways (PATH) program were selected to produce a prototype data set of vehicle trajectories as well as aid in assessing the viability of emerging technologies for automating the trajectory generation process. Vehicle trajectories are needed to...

Effects of Design Elements on Merging Capacity

Skabardonis, A
McDonald, M
1985

A microscope model was developed to simulate traffic behaviour at grade separated interchanges. The model was calibrated and validated from a large UK data base and applied to assess the validity of current ramp entry designs. The significance of design elements such as acceleration lane length, slip road length and gradient was estimated, and it was found that current design practice for ramp entries is generally inadequate. However, some designs would seem to be "more adequate" than others and the results explore the effects of changes in key parameters. (TRRL)

Development of an Arterial Performance Measurement System

Skabardonis, Alexander
Geroliminis, Nikolas
World Conference on Transport Research Society
2007

Recently, an analytical model for real-time estimation of travel times along signalized arterials was developed. The application of the model on two arterial sites and comparisons of the estimated travel times with simulated and field data show that the model accurately predicts travel times on the selected sites. This paper will present several important extensions and refinements to account for the effects of detector placement and queue spillovers. The model is also modified to construct trajectories of individual vehicles in the time-space and estimate queue lengths in a disaggregate...

Development of an Adaptive Control Algorithm for Arterial Signal Control

Amini, Zahra
Mauch, Michael
Skabardonis, Alexander
California PATH
California Department of Transportation
2018

An optimization algorithm was developed to optimize the signal offsets along arterials in real-time based on volume data from loop detectors. The algorithm performance was tested with the VISSIM microscopic model on three real-world arterials. The algorithm generated offsets had better performance than the offsets generated using the widely used SYNCHRO optimization tool. The real-time update of offsets generated by the algorithm was also evaluated using a custom made simulation testbed. The results indicate modest improvements in traffic performance over the SYNCHRO timings. A data...

Developing Improved Truck Passenger Car Equivalent Values at Signalized Intersections

Skabardonis, Alexander
Dowling, Richard
Kiattikomol, Vasin
Safi, Chirag
2014

This paper describes the methodology and findings for developing improved passenger car equivalent (PCE) factors for trucks at signalized intersections on the basis of field data and simulation modeling. The Highway Capacity Manual 2010 (HCM 2010) assumes a single PCE value of 2.00 for trucks at traffic signals. The proposed truck PCE values are sensitive to the proportion of trucks, truck type, and intersection’s approach grade. It is recommended that the current HCM 2010 approach of computing the heavy vehicle and grade effects on saturation flow rates independently be replaced with a...

Design, Field Implementation and Evaluation of Adaptive Ramp Metering Algorithms: Final Report

Horowitz, Roberto
Sun, Xiaotian
Munoz, Laura
Skabardonis, Alexander
Varaiya, Pravin
Zhang, Michael H
Ma, Jingtao
University of California, Berkeley
California Department of Transportation
2006

This report is presented in two parts: Part I: Modeling, Estimation, and Ramp Metering Control of Freeway Traffic, and Part II: Corridor Control Systems. In Part I, the authors develop improved algorithms for freeway on-ramp metering control. Two macroscopic traffic models are presented: a modified cell transmission model (CTM), and a switching-mode model (SMM). A mixture Kalman filter based freeway state estimator is designed to provide estimated vehicle densities and is applied to the Interstate 210 West test site in Pasadena, California. A suite of ramp-metering control algorithms are...

Car-Driver Models for Manual and Automated Travel

Kourjanski, M
Broucke, M
Skabardonis, A
Varaiya, P
Elsevier
1997

This paper presents a model for manual and automated traffic flow. The model is based on the abstraction of vehicle activities by the space and time taken up by the vehicle engaged in the activity. The manual driver model includes the activities of vehicle following and lane change and allows for different levels of aggressiveness of drivers. The parameters of the activities are calibrated with real highway data. The expectation is that this model will provide more realistic estimates of highway capacity while retaining the efficiency of macro-scale simulators.

A Conceptual Simulation Framework for Mobile Radio Communications: A Flexilevel Approach

Silvester, John A.
1997

Mobile radio communications systems are attracting more and more attention since they provide a means for users on the move to exchange information with other stationary or mobile stations. The capability of communication on the move can support many services and create lots of applications. For example, in the future Intelligent Vehicles Highway Systems (NHS), mobile communication technologies have enabled two important subsystems, namely Advanced Traffic Management and Information Systems (ATMIS) and Automatic Vehicular Control Systems (AVCS). The purpose of this research is to develop a...

A Framework for Validating Traffic Simulation Models at the Vehicle Trajectory Level

Xyntarakis, Michalis
Alexiadis, Vassili
Punzo, Vincenzo
Campbell, Robert
Skabardonis, Alex
2017

Based on current practices, traffic simulation models are calibrated and validated using macroscopic measures such as 15-minute averages of traffic counts or average point-to-point travel times. For an emerging number of applications, including connected vehicles, the realism of simulated driver dynamics at the second-by-second or sub-second trajectory level plays an important role. A framework to validate the realism of simulated vehicle dynamics at the trajectory level is presented in this report. Trajectory measures related to safety, comfort, vehicle kinematics, and traffic flow are...

Assessment of Traffic Simulation Models : Final Report

Skabardonis, Alexander
University of California, Berkeley
Washington State Department of Transportation
1999

This report describes a study which focused on the selection and application of traffic simulation models. The models were evaluated for: capabilities and features, input data requirements, output options, relationship with traditional planning and operational analysis tools, and modeling effort and costs.