Traffic Operations and Management

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...

Estimation of Measures of Effectiveness Based on Connected Vehicle Data

Argote, J
Christofa, E
Xuan, Yiguang
Skabardonis, A
Institute of Electrical and Electronics Engineers (IEEE)
2011

Vehicle-infrastructure cooperation via the Connected Vehicle initiative is a promising mobile data source for improving real-time traffic management applications such as adaptive signal control. This paper focuses on developing estimation methods with the use of Connected Vehicle data for several measures of effectiveness (e.g., queue length, average speed, number of stops), essential for determining traffic conditions on urban signalized arterials for real-time applications. This research systematically determines minimum penetration rates that allow accurate estimates for a wide range of...

Estimating the Impacts of Signal Hardware Improvements

Skabardonis, A
1996

Signal equipment upgrades (e.g., multiple timing plan capability and signal interconnection) are commonly used to improve the quality of traffic flow in urban arterials and networks. The findings of the assessment of the effects of alternative control scenarios to assist practicing engineers in conducting analyses to determine the effectiveness of proposed signal equipment upgrades are presented. The effectiveness of hardware improvements was evaluated against the optimal timings with the available equipment to differentiate the benefits from installing hardware from the benefits from...

Estimating Queue Length Under Connected Vehicle Technology: Using Probe Vehicle, Loop Detector, and Fused Data

Li, Jing-Quan
Zhou, Kun
Shladover, Steven E
Skabardonis, Alexander
2013

With the emergence of connected vehicle technology, the use of probe trajectory data to estimate queue length has recently received considerable attention. Unlike data collected by loop detectors, probe trajectory data can provide a lower bound on the queue length even if the market penetration rate is low. An event-based method is developed: it uses both probe trajectory and signal timing data to estimate queue length, and the estimation accuracy under different market penetration rates is examined. A data fusion method is developed: it combines probe trajectory data and loop detector...

Empirical and Analytical Investigation of Traffic Flow Regimes and Transitions in Signalized Arterials

Vlahogianni, Eleni I
Geroliminis, Nikolas
Skabardonis, Alexander
2008

The paper presents a methodological framework that integrates different data-driven techniques in order to detect the different traffic flow regimes (free flow, congested conditions, and so on) observed in signalized arterials as well as the manner traffic flow shifts from one regime to another (transitions). Traffic flow is determined by the joint consideration of the temporal evolution of volume and occupancy. The boundary conditions of the different regimes are identified via a fuzzy wavelet approach based on the volume-occupancy relationship. Moreover, a Bayesian network is developed...

Estimating and Validating Models of Microscopic Driver Behavior with Video Data

Skabardonis, Alex
2005

This report describes the enhancements to the video data collection of the Berkeley Highway Laboratory (BHL), a unique surveillance system on a section of I-80 freeway in the city of Emeryville. We also present the development of advanced machine vision algorithms to process the video data to generate vehicle trajectories. A pilot application of the BHL system produced trajectories of over 4700 vehicles. This is the largest dataset of vehicle trajectories on extended freeway segments. In addition, algorithms and software were developed for data analysis and visualization.

DRBO—A Regional Scale Simulator Calibration Framework Based on Day-to-Day Dynamic Routing and Bayesian Optimization

Jiang, Xuan
Zhao, Yibo
Jiang, Chonghe
Cao, Junzhe
Skabardonis, Alexander
Kurzhanskiy, Alex
Sengupta, Raja
2025

Traffic simulation, a tool for recreating real-life traffic scenarios, acts as an important platform in transportation research. Considering the growing complexity of urban mobility, various large-scale regional simulators are designed and used for research and applications. Calibration is a key issue in the traffic simulation: it finds the optimal system pattern to decrease the gap between the simulator output and the real data, making the system much more reliable. This paper proposes DRBO, a calibration framework for large-scale traffic simulators. This framework combines the travel...

UAV Scheduling Strategies in Multi-modal Last-Mile Urban Parcel Delivery

Li, Ang
Hansen, Mark
2023

Urban parcel delivery has emerged as a high growth market, and the resulting delivery traffic can pose great challenges in dense urban areas. There is growing interest in supplanting the conventional model of a dedicated delivery person operating a van to alternatives featuring new classes of vehicles such as drones, autonomous ground vehicles, cargo bikes and non-motorized vehicles. This work proposes combined delivery strategies using trucks, cargo bikes and drones. We develop and compare multi-modal delivery strategies with various mode combinations. We work on zone-based multi-modal...

Operational Analyses of Freeway Off-Ramp Bottlenecks

Skabardonis, Alexander
Papadimitriou, Fanis
Halkias, Bill
Kopelias, Pantelis
2016

The paper presents the findings to date of operational analyses at freeway off-ramps with emphasis on analysis procedures on recurrent off-ramp bottleneck locations at the Attikiodos motorway (Attica Tollway) in Athens, Greece. The authors compared the observed traffic performance metrics at two sites with the predicted measures using the methodology of freeway diverge areas and weaving sections in the 2010 edition of Highway Capacity Manual (HCM) for a wide range of traffic conditions. The findings indicate that the HCM volume predictions at the diverge area are in close agreement with...

Development of Hardware in the Loop Simulation and Paramics/VS-PLUS Integration

Dickey, Susan
Li, Meng
Yee, Jonathan
Zennaro, Marco
Liu, Hongchao
Chen, Shuaiyu
Lin, Wei-hua
Li, Lefei
2008

The report describes three research efforts carried out under a project titled “Development of Hardware-in-the-Loop (HiL) Simulation and Paramics/VS-PLUS Integration” sponsored by the California Department of Transportation (Caltrans) under Task Order 5311. The first effort developed and evaluated traffic signal optimization with Hardware-in-the-Loop Simulation (HiLS), using the NIATT Controller Interface Device (CID) manufactured by McCain Traffic Supply to provide real-time linkage between the Paramics microscopic simulation and a NEMA TS1 controller. An adaptive control system...