PATH

Command Modification Using Input Shaping for Automated Highway Systems with Heavy Trucks

Bae, Hong S.
Gerdes, J. Christian
2004

Automated vehicles require sufficiently accurate system models in order to achieve a desired level of closed-loop performance in, for example, automated highways systems or smart cruise control systems. Parameters of the models are one of the important factors that determine the accuracy of system modeling and, eventually, the overall performance of the closed-loop system. Current GPS sensing technology enables estimation of road grade and, consequently, simple treatment of parameter estimation from a static force balance. This work has demonstrated that road grade can be reliably...

Optimal Use of Changeable Message Signs for Displaying Travel Times

Ban, Xuegang (Jeff)
Li, Yuwei
Margulici, Jean-Davi
2009

The report describes the research performed and the findings of the PATH Task Order 6303 “Optimal Use of Changeable Message Signs for Displaying Travel Times”. First, travel time estimation methods from various sources are evaluated against probe vehicle data. Next, a survey of San Francisco Bay Area commuters was undertaken regarding the perception and preference for displaying travel times on CMS. Finally, a model that evaluates the CMS impacts on network traffic and determines optimal CMS configurations was developed and tested. Deployment guidelines for CMS are presented based on these...

Freeway Safety as a Function of Traffic Flow: The FITS Tool for Evaluating ATMS Operations

Golob, Thomas F.
Recker, Wilfred W.
Alvarez, Veronica
2002

Understanding the benefits of improved traffic flow (reduced congestion) is critical to the assessment of investments in infrastructure or traffic management and control. Improved flow should lead to reductions in travel time, vehicle emissions, fuel usage, psychological stress on drivers, and improved safety. However, the manner in which safety is improved by smoothing traffic flow is not well understood. The documented research is aimed at shedding light on the complex relationships between traffic flow and traffic accidents (crashes).

Planning the Development of a Commercial Motor Vehicle Virtual Weigh Station Technology Testbed

Miller, Mark A.
Sharafsaleh, Ashkan
2010

This report describes the issues associated with planning the development of a technology testbed for Virtual Weigh Stations in California. These issues may be organized into the following categories: system design and architecture, operational environment, siting & location, data collection, functional requirements and options, technology requirements and options, identification  of  stakeholders,  operational  testing  and  evaluation  (operational  scenarios,  performance measures, benefits &amp...

Development of an Adaptive Corridor Traffic Control Model

Recker, Will
Zhenhg, Xing
Chu, Lianyu
2010

This research develops and tests, via microscopic simulation, a real-time adaptive control system for corridor management in the form of three real-time adaptive control strategies: intersection control, ramp control and an integrated control that combines both intersection and ramp control. The development of these strategies is based on a mathematical representation that describes the behavior of traffic flow in corridor networks and actuated controller operation. Only those parameters commonly found in modern actuated controllers (e.g., Type 170 and 2070 controllers) are considered in...

Vehicle To Roadside Communications Study

Polydoros, Andreas
Dessouky, Khaled
Pereira, Jorge M. N.
Sun, Chung-ming
Lee, Kuo-chun
Papavassiliou, Thomas D.
Li, Victor O. K.
1993

The objective of this study is to address the communication system design issues of Intelligent Vehicle Highway Systems (IVHS). The focus of Phase I of this research is the design for California Advanced Driver Information Systems (CADIS). The emphasis is on the architecture and topology aspects of the physical link and access layers connecting the moving layers with the fixed infrastructure. The work is divided into the following categories: Automatic Vehicle Identification (AVI), IVHS communications survey and functional requirements, modeling of IVHS fading channels, multiple-access...

A Combined Quantitative and Qualitative Approach to Planning for Improved Intermodal Connectivity at California Airports

Lu, Xiao-Yun
Gosling, Geoffrey D.
Ceder, Avi
Tung, Steven
Tso, Kristin
Shladover, Steven
Xiong, Jing
Yoon, Sangwon
2009

This report has been prepared as the final deliverable for a research project developing 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 (IAPT) that combines transportation system performance measurement, an air passenger mode choice model, and a model of transportation provider behavior, and is designed to interface with a traffic network analysis model. The qualitative approach is used to enhance the quantitative...

Determining the Effectiveness of HOV Lanes

May, Adolf D.
Leiman, Lannon
Billheimer, John
2007

This document is the final report for the two-year PATH Project “Determining the Effectiveness of HOV Lanes”. It has been supported by the California Department of Transportation (Caltrans). The primary objectives of this project have been to evaluate freeways having on-freeway HOV lanes in terms of vehicle-travel, person-travel, occupancy distribution, shape and duration of the peak period, congestion patterns, and air quality both in the HOV lane and the adjacent mixed-flow lanes.Based on a comprehensive literature review an extensive list of reference was developed, along with summaries...

Cartesius and CTNET Integration and Field Operational Test

Rindt, Craig R.
McNally, Michael G.
2009

This report describes the results of PATH Task Order 5324—the first year of a multi-year project to integrate the Cartesius incident management system with Cal-trans CTNET traffic signal management system. The results of this research are a set of software requirements for reimplementing the Cartesius to interoperate with CTNET. An analysis of the existing Cartesius prototype explains how the need to focus the system on deployment and technical shortcomings of the existing system justifies a reimplementation of the software. From here, we describe the problem to be solved by the new...

Analysis Toward Mitigation of Congestion and Conflicts at Light Rail Grade Crossings and Intersections

Li, Meng
Wu, Guoyuan
Johnston, Scott
Zhang, Wei-Bin
2009

Although many different railroad grade crossing control products are available, the most challenging limitation to traditional grade crossing systems is their inability to deliver consistent warning times in response to varying train speeds and station stops (particularly nearside stops). As a result, rail-roadway crossings often generate conflicts and congestion for motorist traffic and sometimes delay trains.By conducting system level analysis, this project will investigate the interactions and conflicts between urban/suburban rail and cross traffic. The information that is obtained will...