Traffic Operations and Management

Improving Performance of Coordinated Signal Control Systems Using Signal and Loop Data

Li, Meng
Zhang, Liping
Song, Myoung Kyun
Wu, Guoyuan
Zhang, Wei-Bin
Zhang, Lihui
Yin, Yafeng
2010

In this project, a traffic data collection system based-on the iDEN wireless network has been developed, lab tested and preliminarily tested in the field. The objective of the system is to provide a cost-effective and easy-to-maintain system that could still reliably provide traffic data over the wireless link.The project team developed an arterial performance measurement method that is based on the signal infrastructure data collected at PT2 Lab, U.C. Berkeley. The performance of the proposed model is illustrated by using a simulation study. The six-signal simulation network covers both...

Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies - Phase 1

Ritchie, Stephen G.
Park, Seri
Oh, Cheol
Sun, Carlos
2002

This report presents the results of Phase I of a multi-year research effort on "Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies," and extends previous PATH research by the authors on MOU 336 "Section-Related Measures of Traffic System Performance: Prototype Field Implementation." The focus of this research included the following: significant expansion and enhancement of the ILD-based vehicle reidentification system at a major signalized intersection in Irvine, California to address reidentification of turning vehicles in addition to through...

Integrated Construction Zone Traffic Management

Zhang, Michael
Shen, Wei
Nie, Yu
Ma, Jingtao
2008

Nonrecurrent traffic congestion caused by construction work constitutes a large proportion of the traffic congestion on highways. In TO 5300, we developed a comprehensive work zone traffic impact assessment procedure using a series of state-of-the-art dynamic network analysis tools as building blocks. This procedure is then implemented into a work zone traffic impact assessment software package called NetZone. This software package is capable of estimating time-dependent travel demand based on link counts, estimating demand diversion in response to work zone delay and various traffic...

Opportunities for Improved Intermodal Connectvitiy at California Airports

Lu, Xiao-Yun
Gosling, Geoffrey D.
Xiong, Jing
2006

This working paper has been prepared as part of research to develop a combined quantitative and qualitative approach to planning for improved intermodal connectivity at California airports. The quantitative approach involves the development of an Intermodal Airport Ground Access Planning Tool that combines an air passenger model choice model, a model of transportation provider behavior and a traffic network analysis model. The qualitative approach will be used to enhance the quantitative analysis to account for those factors which are difficult to quantify and to provide recommended policy...

Development and Evaluation of Selected Mobility Applications for VII: Concept of Operations

Shladover, Steven E.
Lu, Xiao-Yun
Cody, Delphine
2009

This report describes the concept of operations for the three mobility applications that PATH is developing and evaluating under the sponsorship of the FHWA Exploratory Advanced Research Program. These applications are intended to use DSRC wireless communications among vehicles and between vehicles and the roadway infrastructure to improve mobility on limited-access highways. The first application combines ramp metering with variable speed limits to enhance control of traffic so that traffic flow breakdowns can be deferred or avoided at bottleneck locations. The second application uses...

Establishing Infrastructure Requirements for Bus Rapid Transportation Operations in Dedicated Bus Lanes

Monismith, Carl L., P.E.
Weissman, Shmuel L., PhD
Popescu, Lorina
Santero, Nicholas J.
2008

Bus Rapid Transit (BRT) has the potential to improve mass transit service and contribute to reduced traffic congestion in urban areas. To achieve this improvement in service BRT will require the use of dedicated bus lanes together with lane assist and precision docking (LA/PD) to accelerate the passenger boarding process. Using this approach, BRT lanes can be reduced somewhat in width. However, such a reduction will result in increased channelization of traffic which in turn can lead to a more rapid development of pavement distress. With today’s improved pavement engineering technology, it...

Vehicle-based Control Computer Systems

Auslander, David M
1995

This report is presented in two parts: the first part describes a design and implementation methodology for real time software suitable for control of mechanical systems such as vehicles. This method provides for a design description of the system, a means of capturing the system structure in such a way as to modularize the software writing job, and a portable implementation method. The second part is concerned with a particular problem in the mechanical system control: estimating velocity when the even rate from a digital encoder is lower than the controller's sample time. Methods are...

Evaluation of Caltrans District 10 Automated Warning System: Year Two Progress Report

MacCarley, Art
1999

District 10 of the California Department of Transportation (Caltrans) encompasses an area of seasonal fog and dust-related visibility problems that have been the cause of numerous multi-car traffic collisions, many fatal. In 1990, motivated by the expansion of State Route 120 (SR 120) connecting Interstate Highway 5 (I-5) and State Route 99 (SR 99), Caltrans proposed a sophisticated multi-sensor automated warning system as a means for reducing incidents in this high-traffic area. This proposal, and the significant development effort that followed, culminated in the implementation of Phase...

Adaptive Throttle Control For Speed Tracking

Xu, Z.
Ioannou, P.
1994

In this paper, the authors design an adaptive control scheme for electronic throttle that achieves good tracking of arbitrary constant speed commands in the presence of unknown disturbances. The design is based on a simplified linear vehicle model which is derived from a validated nonlinear one. The designed control scheme is simulated using the validated full order nonlinear vehicle model and tested on an actual vehicle. The simulation and vehicle test results are included in this paper to show the performance of the controller. Due to the learning capability of the adaptive control...

Effects of Cooperative Adaptive Cruise Control on Traffic Flow: Testing Drivers' Choices of Following Distances

Shladover, Steven E.
Nowakowski, Christopher
Cody, Delphine
Bu, Fanping
O’Connell, Jessica
Spring, John
Dickey, Susan
Nelson, David
2009

A Cooperative Adaptive Cruise Control (CACC) system has been developed by adding a wireless vehicle-vehicle communication system and new control logic to an existing commercially available adaptive cruise control (ACC) system. The CACC is intended to enhance the vehicle-following capabilities of ACC so that drivers will be comfortable using it at shorter vehicle-following gaps than ACC. If this is shown to be the case, it offers a significant opportunity to increase traffic flow density and efficiency without compromising safety or expanding roadway infrastructure.This report describes the...