PATH

Integrated Roadway / Adaptive Cruise Control System: Safety, Performance, Environmental and Near Term Deployment Considerations

Zhang, Jianlong
Ioannou, Petros
2004

In this project, we design two new Adaptive Cruise Control (ACC) systems based on driver comfort, safety, vehicle following performance, environmental and traffic flow characteristics considerations. A new variable time headway rule is proposed and used to meet these considerations. Analysis and simulations are used to evaluate and compare the two designs. The first ACC system (referred to as ACC01) incorporates two controllers: one for speed tracking and one for vehicle following. The second ACC system (referred to as ACC02) treats the vehicle following task as a special speed tracking...

Longitudinal Model Development For Automated Roadway Vehicles

Mcmahon, Donn H.
Hedrick, J. K.
1990

In today’s society minimizing the use of the roadways is becoming an issue of increasing concern.Many major cities in the US are plagued with such problems as traftic congestion, poor air quality, andsafety problems. To solve these problems research throughout the world is being conducted on the use ofautomated roadways.Currently in the state of California research is being conducted involving several major institutionsas to the feasibility of the automated roadway. The Program on Advanced Technology for the Highway,PATH, aims to increase the capacity of the most used highways, to decrease...

Transit Integrated Collision Warning System Volume I: System Development

Chang, Joanne
Dicky, Susan
Duncil, Bart
Johnston, Scott
Kretz, Paul
Lian, Thang
Lu, Xiaoyun
Marco, David
Nelson, David
Shladover, Steven
Zhang, Wei-Bin
Zhang, Yongquan
Duggins, Dave
Gowdy, Jay
Hebert, Martial
Kozar, John
MacLachlan, Rob
Metz, Christoph
Steinfeld, Aaron
Suppe, Arne J
Burton, Frank
DeBone, Dan
Snyder, Rick
2007

Based on the foundation of the frontal and side collision warning systems, the Frontal Collision Warning System (FCWS) and Side Collision Warning System (SCWS) teams joined efforts to improve the collision warning algorithms. The objective of the ICWS Program is to study how frontal and side collision warning system might interface with each other, and to develop prototype ICWS systems on two buses, one at Samtrans and the other at PAT. The prototype ICWS buses have been in revenue operation in the Bay Area and Pittsburgh to collect field operational data and driver responses. The results...

Health of California’s Loop Detector System

Rajagopal, Ram
Varaiya, Pravin
2007

The California Department of Transportation (Caltrans) freeway sensor network has two components: the sensor system of 25,000 inductive loop sensors grouped into 8,000 vehicle detector stations (VDS) and covering 30,500 freeway direction-miles; and the communication network over which the sensor measurements are transported to Caltrans Traffic Management Centers. The sensor network is virtually the only source of data for use in traffic operations, performance measurement, planning and traveler information. However, the value of these data is greatly reduced by the poor reliability of the...

WTRP-Wireless Token Ring Protocol

Ergen, Mustafa
2002

WTRP (Wireless Token Ring Protocol) is a medium access control (MAC) protocol for wireless networks. The MAC protocol through which mobile stations can share a common broadcast channel is essential in wireless networks. In a IEEE 802.11 network, the contention among stations is not homogeneous due to the existence of hidden terminals, partially connected network topology, and random access. Consequently, quality of service (QoS) is not provided. WTRP supports guaranteed QoS in terms of bounded latency and reserved bandwidth which are crucial real time constraints of the applications. WTRP...

Light Rail System Safety Improvements Using ITS Technologies

Chira-chavala, Ted
Coifman, Ben
Empey, Dan
Hansen, Mark
Lechner, Ed
Porter, Chris
1997

This report describes research which studied identifying and analyzing the effectiveness of countermeasures designed to reduce light rail crashes. Focus is in collisions with road vehicles at intersections. The light rail system for the Santa Clara County Transportation Agency in California served as the focus of the study.

A Cost-effective Traffic Data Collection System Based on the iDEN Mobile Telecommunication Network

Zhang, Liping
Li, Meng
Lau, Peter
Zhang, Wei-Bin
Leung, Kai
2008

This report describes a cost-effective data collection system for Caltrans 170 traffic signal controller. The data collection system is based on TCP/IP communication over existing low-cost mobile communication networks and Motorola® iDEN1 mobile handsets. An adaptive wireless flow control protocol is developed to ensure reliable continuously communication over unstable wireless link. The system is fully integrated with Caltrans 170 signal controllers and its CTNet server program. Lab testing shows that with the adaptive flow control protocol, each handset can deliver data fetched from...

University of California, Davis Long-Range Development Plan: A Davis Smart Mobility Model

Shaheen, Susan
Rodier, Caroline J.
Finson, Rachel S.
2003

The goal of the Smart Mobility Model project was to optimize individual mobility options through improved connectivity among modes, enhanced techniques to link landuse 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) was initiated after 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...

Developing Calibration Tools for Microscopic Traffic Simulation Final Report Part III: Global Calibration - O-D Estimation, Traffic Signal Enhancements and a Case Study

Zhang, Michael
Ma, Jingtao
Singh, Shailendra P.
Chu, Lianyu
2008

The central goal of this research is to develop a systematic framework and the support tools to ease, streamline and speed up the calibration of micro simulation projects. Part III of the final report documents the accomplishments achieved in the second phase of the research project. They include the following.First, to overcome the lengthy time it takes for GA to obtain local and global driving behavior modeling parameters, we implemented a faster heuristic optimization technique, the simultaneous perturbation stochastic approximation (SPSA) and compared its performance with other...

Fault Detection And Tolerant Control For Lateral Guidance Of Vehicles In Automated Highways

Patwardhan, Satyajit Neelkanth
1994

In this dissertation, the problem of fault tolerant control of automobiles is addressed. The three main problems handled in the dissertation are tire burst, sensor fault detection and slip angle control. The tire burst and sensor faults are important failure modes for automated highways, whereas the slip angle control problem is important during severe maneuvers for enhancing the vehicle safety.