PATH

Systematic Design for Roadway Interfaces with Applications to Automated Highways

Hall, Randolph
2000

This report provides interim results on the design of interfaces between automated highways and conventional street systems. The purpose here is to identify the strategic issues in interface design, and to provide preliminary analysis on just one of these issues (separation between highway entrance and exits). Future research will explore a full set of strategic issues in greater depth. The central concept explored in this report is how to design a roadway system that comprises multiple layers, some of which are designed for the purpose of accessibility, and others of which are designed...

Determining the Capacity Benefits of Real-time Signal Control at Intersections

Skabardonis, Alexander
Gallagher, Brian R.
Patel, Kartik P.
2000

Traffic responsive control strategies are increasingly being implemented to improve intersection performance. Critical intersection control (CIC) is using real-time traffic data to better assign green times to conflicting movements. However, the benefits of CIC have not been assessed, and existing methodologies for estimating intersection performance do not account for CIC or other traffic responsive control strategies. The effectiveness of CIC was evaluated at seven signalized intersections in the City of Los Angeles. The findings indicate that CIC generally improves traffic operations....

Development Testing And Evaluation Of Advanced Techniques For Freeway Incident Detection

Ritchie, Stephen G.
Abdulhai, Baher
1997

In this research, the authors introduce and define a universal incident detection framework that is capable of fulfilling all components of a set of recognized needs. An algorithm is presented that has the potential to fulfill the defined universality requirements. It is a modified form of a probabilistic neural network (PNN) that utilizes the concept of statistical distance. The first part of the report presents a definition of the attributes and capabilities that a potentially universal freeway incident detection framework should possess. The second part discusses the training and...

An Assessment of Bus Rapid Transit Opportunities in the San Francisco Bay Area

Miller, Mark A.
White, Dustin
2004

This report documents a continuing assessment of bus rapid transit opportunities in the San Francisco Bay Area. In this study we are focusing on bus transit routes that partially travel on California state routes, whether arterial roadways or freeways. A primary component of this project is to consider the inter-connectivity and regional aspects of bus rapid transit systems deployment in the San Francisco Bay Area region. Considering state routes will help identify more regional opportunities for innovative types of partnerships to help address unmet public transit service needs across...

Ultrasonic Ranging Control Board Documentation

Chen, Jennie
Foreman, Bret
Mostov, Kirill
1994

This document specifies the theory of operation of version B of the PATH ultrasonic range control board for the IBM PC. Two modes are discussed in detail. The first is the ping mode, which uses a single transducer both to send an ultrasonic pulse and receive its echo. The second, called the phased-array mode, uses a single transducer to send the pulse and two other transducers to receive echoes and perform path-length matching in order to reduce the effects of multi-path echoes. Both the hardware and the software used to perform these functions are examined.

Transient Aerodynamics in Vehicle Interactions: Data Base Summary

Chen, A.L.
Hedrick, K.
Savas, O.
1998

The vehicles in a platoon will experience transient aerodynamic forces as vehicles leave and join the platoon at various locations. A platoon of scale vehicle models is placed in a wind tunnel and measurements are made of the transient forces and moments as one of the vehicles is moved into and out of the platoon. The results from the wind tunnel experiments will allow the computer vehicle control algorithms to better predict the transient aerodynamics the vehicles in the platoon will encounter during leaving and joining maneuvers.Since a lane change (either leaving or joining a platoon)...

Lessons From Case Studies Of Advanced Transportation And Information Systems

Dahlgren, Joy
Weissenberger, Stein
Hickman, Mark
Lo, Hong
1996

This paper poses two key questions regarding ATMIS implementation: how are ATMIS services successfully implemented?, in what circumstances are ATMIS strategies cost-effective? The authors attempt to find answers by examining case studies of twelve jurisdictions. The answers should help others judge where and how ATMIS should be implemented. The first section of the paper identifies the requirements for successful ATMIS implementation and operation based on the case study findings. The second describes a diffusion pattern found in the case studies. The final section concludes that more is...

Decision Support Systems for Managing and Applying ITS Research

Dahlgren, Joy
AlKadri, Mohamed
Picado, Rosella
1998

This study is presented in three related papers. The first develops a structure for making decisions regarding Caltrans/PATH research. It describes a research cycle in which real world needs and opportunities fed into a process by which research priorities are set, proposals invited, and projects are selected. These research projects ultimately provide information that can be used for further research or for implementation. Implementation changes society and technology and leads to new needs and opportunities, which in turn feed into the research process. The second paper develops and...

Identification and Prioritization of Environmentally Beneficial Intelligent Transportation Technologies: Modeling Effort

Young, Troy
Sperling, Daniel;
Shaheen, Susan
1999

In 1996, California Partners in Advanced Transit and Highways (PATH) commissioned a project team led by the Institute of Transportation Studies, University of California at Davis with the Claremont Graduate School to undertake a review of the environmental impacts of Intelligent Transportation Systems (ITS). The objectives of this project were to: 1) review previous qualitative and quantitative environmental assessments of ITS, from both field operational tests and modeling studies; 2) review the regulatory and policy contexts which encompass ITS; 3) develop a modeling framework suitable...

AHSCAP Dynamic Traffic Assignment Program User’s Manual and Design Description

Hongola, Bruce
1996

This research seeks to provide an understanding of the capacity and throughput require- ments of an automated highway system(AHS) via development of a computer model that represents system capacity and demand, operational characteristics, and defined infras- tructure. To do that, a variety of scenarios representing traffic input to the system must be represented. Also, a variety of infrastructures representing different system configurations must be represented. This includes the locations of entrances and exits.Detailed vehicle-based simulations have been used to investigate AHS capacity...