Roads/Highways

Evaluation of Magnetic Markers as a Position Reference System for Ground Vehicle Guidance and Control

Chan, Ching-Yao
Tan, Han-Shue
2003

This report contains an evaluation of the sensing techniques and implementation issues of magnetic sensing as a position reference system. The field patterns of sample magnetic markers were first measured to illustrate the basic characteristics of such systems. Several sensing approaches were explained and compared with regard to their functioning principles and sensitivity to measurement variations. Three particular algorithms were discussed with illustrations of respective mapping methods. Robustness and sensitivity of the sensing methods, when subject to signal noises and parameter...

Commercially-off-the-Shelf (COTS) and Emerging Technologies Sensor Testing and Evaluation

Sharafsaleh, Ashkan
2006

This report addresses Task S of the Intersection Decision Support (IDS) project funded by Federal Highway Administration (FHWA) and Caltrans. The objective of Task S is to evaluate and select Commercially-Off-The-Shelf (COTS) and emerging technology products that could eventually be deployed at intersections as part of the IDS system. Many sensors were considered and every plausible detection technology was reviewed for this task. The emphasis was on finding sensors that detect and track vehicle movements.This effort started with establishing a background and general guidelines for what...

An Evaluation of the Consequences and Effectiveness of Using Highway Changeable Message Signs for Safety Campaigns

Rodier, Caroline, PhD
Finson, Rachel S.
Lidicker, Jeffrey
Shaheen, Susan A., PhD
2010

Changeable Message Signs (CMSs), which are also called dynamic or variable message signs, are programmable signs used on highways worldwide to provide drivers with real-time information, such as traffic updates, roadwork warnings, and other traffic and safety-related information. CMSs allow motorists to take immediate action in response to information—to slow down or change routes, for example, which leads to safer driving conditions and less congestion. More recently, in California and throughout the U.S., CMSs have been used as part of public campaigns to promote roadway safety by...

Fuzzy Logic Traction Controllers And Their Effect On Longitudinal Vehicle Platoon Systems

Bauer, M.
Tomizuka, M.
1995

This paper presents fuzzy logic traction controllers and their effect on longitudinal vehicle platoon systems. A fuzzy logic approach is appealing for traction control because of the non-linearities and time-varying uncertainties in traction control systems. One fuzzy controller estimates the "peak slip" corresponding to the maximum tire-road adhesion coefficient and regulates wheel slip at that value. The other fuzzy logic controller regulates wheel slip at any desired value. The controllers' performance and robustness against changing road conditions and time- varying uncertainty is...

Small Cars In Neighborhoods

Bosselmann, Peter C.
Cullinane, Daniel
Garrison, William L.
Maxey, Carl M.
1993

Focusing on neighborhood travel, this study first reviews the development of vehicles and roads suited to such travel. It then considers community development trends that might encourage or thwart the adoption and use of such vehicles. Demands for vehicles and travel patterns are then treated, followed by discussions of safety and regulation topics and cost benefit issues.

Davis Smart Mobility Model Project: Initial Scoping and Planning Study

Shaheen, Susan A.
Finson, Rachel S.
2003

The goal of the Davis Smart Mobility Model project is to optimize individual mobility options through improved connectivity among modes, enhanced techniques to link land-use planning and transportation system design, advanced information technologies, and clean-fuel vehicles. The California PATH/Caltrans partnership with the University of California, Davis (UC Davis) started when campus planners expressed interest in learning how innovative mobility services and technologies (such as carsharing and smart parking management) might help to alleviate the transportation impacts of a campus...

Nonlinear Longitudinal Controller Development and Real-time Implementation

Lu, Xiao-Yun
Tan, Han-Shue
Empey, Dan
Shladover, Steven E.
Hedrick, J. Karl
2000

Keywords longitudinal control, car platooning, back-stepping control, multi-surface dynamic sliding mode control, integral filters, realtime control code This report presents the development of nonlinear longitudinal controllers and their realtime implementation for Automated Highway Systems (AHS) at PATH, U. C. Berkeley supported by the project MOU 331. The demo'97 realtime code was first reconstructed for further development. Based on the new framework, the implementation and comparison of nonlinear controllers in the longitudinal control for cars platooning and other maneuvers have been...

Commercial Motor Vehicle Inspection and Screening Stations: Evaluating Performance from the Perspective of Practitioners

Miller, Mark A.
Garefalakis, Antonios
2009

This report presents the findings of a study of commercial motor vehicle inspection and screening station practices with a focus on the use of various technologies to help address problems related to safety, security, roadway infrastructure, and air quality. A review of industry literature identified the various types of inspection and screening practices that have been and are being implemented including weight and size management, on-board equipment checking, driver-related violations and cargo monitoring, credential checking, and exhaust emissions monitoring. The review also identified...

California Intersection Decision Support: A Driver-Centered Approach to Left-Turn Collision Avoidance System Design

Bougler, Bénédicte
Cody, Delphine
Nowakowski, Christopher
2008

Currently, Federal and State governments are partnering with private industries and academia institutions to pursue the deployment of intersection decision support (IDS) and cooperative intersection collision avoidance systems (CICAS), which seek to combine infrastructure-based and vehicle-based functions to provide optimal solutions for roadway users. The overall (IDS) research plan was constructed to explore the requirements, tradeoffs assessment, and technology investigations necessary to define a Cooperative Intersection Collision Avoidance System. This report is the third report on...

Evaluation And Analysis Of Automated Highway System Concepts And Architectures

Ioannou, Petros
1998

This is the final report for the project entitled \Evaluation and Analysis of Automated Highway System Concepts and Architectures" in response to the contractual requirements of the Memorandum of Understanding MOU# 235, between the Partners of Advanced Transit and Highways (PATH) and the University of Southern California, administered at the University of Califor- nia at Berkeley. The purpose of this project was to select, evaluate and analyze a num- ber of promising Automated Highway System (AHS) operational concepts based on previous work. The evaluation and analysis includes headway dis...