Data

Determining the Capacity Benefits of Real-time Signal Control at Intersections

Skabardonis, Alexander
Gallagher, Brian R.
Patel, Kartik P.
2000

Traffic responsive control strategies are increasingly being implemented to improve intersection performance. Critical intersection control (CIC) is using real-time traffic data to better assign green times to conflicting movements. However, the benefits of CIC have not been assessed, and existing methodologies for estimating intersection performance do not account for CIC or other traffic responsive control strategies. The effectiveness of CIC was evaluated at seven signalized intersections in the City of Los Angeles. The findings indicate that CIC generally improves traffic operations....

Development Testing And Evaluation Of Advanced Techniques For Freeway Incident Detection

Ritchie, Stephen G.
Abdulhai, Baher
1997

In this research, the authors introduce and define a universal incident detection framework that is capable of fulfilling all components of a set of recognized needs. An algorithm is presented that has the potential to fulfill the defined universality requirements. It is a modified form of a probabilistic neural network (PNN) that utilizes the concept of statistical distance. The first part of the report presents a definition of the attributes and capabilities that a potentially universal freeway incident detection framework should possess. The second part discusses the training and...

Transient Aerodynamics in Vehicle Interactions: Data Base Summary

Chen, A.L.
Hedrick, K.
Savas, O.
1998

The vehicles in a platoon will experience transient aerodynamic forces as vehicles leave and join the platoon at various locations. A platoon of scale vehicle models is placed in a wind tunnel and measurements are made of the transient forces and moments as one of the vehicles is moved into and out of the platoon. The results from the wind tunnel experiments will allow the computer vehicle control algorithms to better predict the transient aerodynamics the vehicles in the platoon will encounter during leaving and joining maneuvers.Since a lane change (either leaving or joining a platoon)...

Berkeley Highway Lab Videl Data Collection System

Chen, Chao
Lyddy, Daniel
Dundar, Baris
2004

The goal of this project is to replace the existing analog video collection system on the roof of Pacific Park Plaza (PPP) with a digital one. This video collection system is part of the Berkeley Highway Laboratory (BHL) testbed. It records video of traffic on a continuous one-kilometer section of Interstate 80 (I-80) near Emeryville, CA. This section of I-80 features on-ramps, off-ramps, and weaving zones. The video of interactions between vehicles can be fed to a machine-vision system, which generates vehicle trajectories to be used in a variety of traffic studies. The video itself can...

Simulation Modeling Of The Santa Monica Freeway

Bloomberg, Loren D.
May, Adolf D.
1994

As part of a project investigating the benefits of Intelligent Vehicle Highway Systems (IVHS) technology using simulation, two models of the Santa Monica Freeway in Los Angeles were developed. This report describes the work performed to create, test, and apply these simulations. Two independent simulations were coded, using FREQ and INTEGRATION models, from the available data. The report describes the strategies, limitations, and assumptions needed to code the Santa Monica Freeway using the two simulation tools. After coding the models, calibrating the output to match traffic performance...

Validation of the Incremental Transfer Model

Robert, Tim
Lin, Wei-Hua
Cassidy, Michael
1999

This report documents our validation effort on the Incremental Transfer (IT) model, which is a macroscopic traffic flow model capable of handling freeway systems with special lanes and priority vehicles. The validation study is performed with field data from a 1.7-mile long freeway segment with a congested off-ramp in Oakland, California. In our study, vehicles exiting the off- ramp of this segment are treated as "regular vehicles" and through vehicles as "special vehicles." By assuming that the exiting or "regular" vehicles must stay on the "near" side lanes, we examine the spatial...

Analysis Of Arterial Street Data From The ATSAC System

Bacon, Jr., Vinton W.
May, Adolf D.
1993

This study is part of an effort to simulate the Santa Monica Freeway Corridor in Los Angeles using the INTEGRATION model. The purpose of this report was to develop an efficient process of data extraction to be used for future use and to test the integrity of the data itself.

Orange County Transit/traffic Management Integration And Traveler Information Project: Evaluation Plan

Hall, R.
Hickman, M.
1996

This document focuses on a Field Operational Test (FOT) to develop an integrated information system for transit and traffic management and for traveler information that relies on Global Positioning System (GPS) equipped buses as probe vehicles. The document provides the evaluation plan for the FOT. The plan covers three principal elements: 1) Institutional, TMC Operator and Bus Operator, 2) Public Knowledge and Perceptions, and 3) System performance. The document provides an overall evaluation framework that describes how the evaluation elements will assess project objectives. In addition...

An Enhancement to Speed Estimation with Single Loops

Lin, Wei-Hua
Dahlgren, Joy
Huo, Hong
2003

Traffic data from single loop detectors are one of the dominant data sources widely used in many traffic operation centers and traveler information systems. Speed estimation from single loop detectors is mainly based on occupancy data, a conversion factor from occupancy to density (which is related to vehicle length), and the assumed relationship between flow, speed, and density. This paper investigates the discrepancy between the speed estimated with single loops and the speed measured directly from double loops. It was found that the inaccuracy of speed estimation with single loops is...

Vehicles As Probes

Sanwal, Kumud K.
Walrand, Jean
1995

In this paper, the authors discuss the use of vehicles moving in traffic as probes that provide data for estimation and prediction of traffic behavior. The probe vehicles can report data on their speeds, locations, or travel times which can be used by an algorithm that updates estimates of traffic state and makes predictions for the future. The authors address some of the key issues involved in the design of such a traffic monitoring system.