Data

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.

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)

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 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...

Detecting Errors and Imputing Missing Data for Single-Loop Surveillance Systems

Chen, Cong
Kwon, J
Rice, J
Skabardonis, A
Varaiya, P
Transportation Research Board
2003

Single-loop detectors provide the most abundant source of traffic data in California, but loop data samples are often missing or invalid. A method is described that detects bad data samples and imputes missing or bad samples to form a complete grid of clean data, in real time. The diagnostics algorithm and the imputation algorithm that implement this method are operational on 14,871 loops in six districts of the California Department of Transportation. The diagnostics algorithm detects bad (malfunctioning) single-loop detectors from their volume and occupancy measurements. Its novelty is...

Connected Vehicle Penetration Rate for Estimation of Arterial Measures of Effectiveness

Argote-Cabañero, Juan
Christofa, Eleni
Skabardonis, Alexander
2015

The Connected Vehicle (CV) technology is a mobile platform that enables a new dimension of data exchange among vehicles and between vehicles and infrastructure. This data source could improve the estimation of Measures of Effectiveness (MOEs) for traffic operations in real-time, allowing to perfectly monitor traffic states after being fully adopted. However, as with any novel technology, the CV adoption will be a gradual process. This research focuses on determining minimum CV technology penetration rates that would guarantee accurate MOE estimates on signalized arterials. First, the...

Connected & Autonomous Vehicles – Environmental Impacts – A review

Kopelias, Pantelis
Elissavet, Demiridi
Vogiatzis, Konstantinos
Skabardonis, Alexandros
Zafiropoulou, Vassiliki
2020

Over the last decades the vehicle industry has shown interest in integrating new technologies on vehicles’ design. Such technologies are used in autonomous, connected and electrical vehicles with the primary hope of improving road safety and the environmental impact of road traffic. Regarding the environmental impact, the transport sector has been considered responsible for Greenhouse Gas emissions for the past thirty years or more, and efforts have been made to reduce impacts of such emissions on the environment. The environmental noise is also associated with road traffic and its effects...