PATH

Distributed Surveillance and Control on Freeways

Coifman, Benjamin
2004

Efficient management of a road network requires continuous decision-making based on conditions on the network and an understanding of the impacts of the decisions made. These conditions are usually measured with fixed-point surveillance systems, most of which are deployed in such a manner as to require communication links that are always connected and are polled at regular intervals. All of the sensor data are typically sent to a Traffic Management Center (TMC) for assessment, yet most of the time no action is taken in response to the data, leading to unnecessarily high communication costs...

Travel Times on Changeable Message Signs: Pilot Project

Chen, Chao
2004

We describe a system to display real time travel times on Changeable Message Signs (CMS) in California. CMS's show dynamic information and allow the Traffic Management Center (TMC) to communicate to drivers information about traffic diversion, incidents, and delays. This type of service is deployed in other parts of the country and world and has been shown to be useful. For this project, we implemented a system that uses existing algorithms for travel time estimation and prediction.

Effectiveness of VMS Using Empirical Loop Detector Data

Huo, Hong
Levinson, David
2006

This study employs traffic data and incident data from the Twin Cities of Minneapolis and St. Paul, Minnesota. The conclusion in this study provides guidance on making policy about investing in VMS systems.Few studies utilize empirical traffic data. They either use costly surveys or conduct traffic simulation, which are expensive and may not conform well to reality. This study uses empirical traffic flow and occupancy data on both mainline and ramps, collected every 30 seconds to estimate the effectiveness of VMS. The variation of diversion rate before and after warning messages is...

Augmented Speed Enforcement Project at UC Berkeley - Executive Summary

Chan, Ching-Yao
Gupta, Somak Datta
2015

In this project, a speed alert and augmented enforcement system (aSE) was developed with a combination of sensing, image processing and recognition, wireless communication. The system includes a speed camera that captures speeding vehicles, and a changeable message sign that displays speeder’s license plate number and measured speed, and a web page that allows police officers to monitor the incidence of violators traveling at excessive speeds. The aSE system was field tested for a work zone application on a rural highway. With data collected over multiple weeks, under a baseline scenario...

Analysis of Traffic Flow With Mixed Manual and Intelligent Cruise Control Vehicles: Theory and Experiments

Bose, Arnab
Ioannou, Petros
2001

During the last decade considerable research and development efforts have been devotedto automating vehicles in an effort to improve safety and efficiency of vehicular traffic.While dedicated highways with fully automated vehicles is a future objective, theintroduction of Intelligent Cruise Control (ICC) vehicles on current highways designed tooperate with manually driven vehicles is a realistic near term objective. The purpose ofthis report is to analyze the effects on traffic flow characteristics and environment whenICC vehicles with automatic vehicle following capability (in the same...

Virtual Weigh Stations in California: A Preliminary Cost-Effectiveness Analysis

Santero, Nicholas
Nokes, William
Harvey, John
2005

A new technology known as Virtual Weigh Stations (VWS) is intended to transform data-collecting weigh-in-motion (WIM) sites to weight enforcement mechanisms. This study investigates the possible benefits to the highway pavements in California from potential use of VWS. The investigation proceeded in two steps: (1) determining the damage currently caused by overweight trucks and (2) modeling the potential pavement life saved with VWS. The data used for analysis is from the California Department of Transportation (Caltrans) WIM database.

Parameter Estimation and Supervisory Techniques for Robust Longitudinal Control of Heavy Vehicles

Druzhinina, Maria
Moklegaard, Lasse
Stefanopoulou, Anna G.
2003

This report describes the development and experimental validation of a coordination scheme between friction and discretely variable compression brakes for a Class 8 Freightliner truck used as a development platform in the California PATH program. The coordination scheme that we developed maintains the speed tracking performance of the nominal PID controller which was originally designed by the UCLA team for the case of friction brakes only. Through the coordination scheme, the command of the nominal PID controller is split into a friction brake command and compression brake command. The...

Safety Analysis of Concept Systems for Guidance and Control of Transit Buses

Michael, James Bret
1997

This study reports on a method to accomplish sensor validation and fusion in Intelligent Transportation Systems (ITS). The method is based on probabilistic and fuzzy techniques that express a confidence in the sensor data and take into account environmental factors and the state of the system. Sensor data fusion uses the confidence assigned to each sensor reading and integrates them into one reading. Noise and failure are filtered from the data and lead to a safety improvement in ITS.

Bicycle Detection and Operational Concept at Signalized Intersections Phase 2

Shladover, Steven E.
Kim, ZuWhan
Cao, Meng
Sharafsaleh, Ashkan
Li, Irene
Johnston, Scott
1997

This study reports on a method to accomplish sensor validation and fusion in Intelligent Transportation Systems (ITS). The method is based on probabilistic and fuzzy techniques that express a confidence in the sensor data and take into account environmental factors and the state of the system. Sensor data fusion uses the confidence assigned to each sensor reading and integrates them into one reading. Noise and failure are filtered from the data and lead to a safety improvement in ITS.

Evaluation of ITS Technology for Bus Transit Systems

Hall, Randolph
Dessouky, Maged
Zhang, Lei
Singh, Ajay
Patel, Vishal
1999

Recently, bus transit service providers have begun to adopt Intelligent Transportation Systems (ITS) technologies such as Global Positioning Systems (GPS) and Mobile Data Terminals. These systems taken together have the potential to reduce the cost of providing transportation services through the execution of real-time control strategies, performance monitoring systems and data collection to support service realignment. We evaluate bus control strategies using ITS against those without ITS. Two levels of ITS are considered: (1) system with centralized tracking and (2) system with...