Traffic Operations and Management

TravInfo Evaluation: Traveler Response Element Broad Area Study: Phase 2 Results Analysis of Wave-2 Survey

Yim, Y. B.
2001

TravInfo was a Field Operational Test (FOT) sponsored by the Federal Highway Administration (FHWA) and California Department of Transportation. It aimed to develop a multi-modal traveler information system for the San Francisco Bay Area, combining public and private sector talents. The Broad Area Study was part of the TravInfo FOT evaluation. It addressed issues on how travelers obtain traffic/transit information and how the information influences travel behavior. Two waves of telephone surveys of Bay Area households were conducted, one prior to and one after the Field Operational Test....

Modeling The Behavior Of Traffic Information Providers

Malchow, M.
Kanafani, A.
Varaiya, P.
1997

This paper discusses two primary models which might be used to represent the locational behavior of traffic information providers. The characteristics which make traffic information unique as a service good are discussed and exploited in the models to show how the behavior of information providers might differ from that of firms in a traditional market. Questions are addressed regarding the clustering of competing providers and the efficiency of resulting output. The purpose of this paper is to contribute to a study regarding the future of the traffic information industry and the role of...

PATH ATMIS State of the Research Annual Report Fiscal Year 1999 / 2000

Tam, Robert
2000

This report summarizes PATH ATMIS research for fiscal year 1999/2000. In each of the brief project descriptions we state the objectives of the project and outline its status and some of its principal results. These descriptions are not intended to be comprehensive or complete, but rather to present a picture of the main thrusts of each of the reported projects. References are provided in the end of the report for more detailed information about particular projects. Taken together, the collection of project descriptions should give the reader an overview of the entire ATMIS research program...

Properties of Link Travel Time Functions Under Dynamic Loads

Daganzo, Carlos F.
1993

This note examines a general form of link travel time functions considered in the dynamic traffic assignment literature and shows that it only makes some physical sense in the special case where each function denotes either a link with no spatial dimension containing a point queue, or a link with constant travel time and no queueing. Roadway segments exhibiting both phenomena must be represented by two links in series.

Structure of the Transition Zone Behind Freeway Queues

Munoz, Juan Carlos
Daganzo, Carlos
2000

Observations of freeway traffic flow are usually quite scattered about an underlying curve when plotted versus density or occupancy. Although increasing the sampling intervals can reduce the scatter, whenever an experiment encompasses a rush hour with transitions in and out of congestion, some outlying data stubbornly remain beneath the "equilibrium" curve. The existence of these non-equilibrium points is an ill-understood phenomenon that appears to contradict the simple kinematic wave (KW) model of traffic flow. This paper provides a tentative explanation of the phenomenon, based on...

Current and Future Transportation Management High-Level Requirements Technical Memorandum

Zeinali Farid, Yashar
Peterson, Brian
Harrington, Michelle
2021

This document presents a review of the current and future requirements for information exchange between traffic management centers, with emphasis on the changes expected due to the changing nature of transportation and the advances in technology that are becoming prevalent in the transportation ecosystem. The intent of this document is to provide a look at the source of changes required within center-to-center communication and new requirements that will need to be addressed as transportation undergoes significant change due to new transportation modes, technology advances in connected and...

Modernization of Center-to-Center Data Communication Standards: Sample Implementation Administration and User Guide

Peterson, Brian
2021

This document provides a guide to the reference sample application developed under the Traffic Management Data Dictionary (TMDD) modernization contract. The application provides a sample implementation of a SOAP implementation using the XML Schema Definition (XSD) and Web Service Description Language (WSDL) developed under the contract. In addition, it provides a sample implementation of a Kafka/JSON based messaging implementation. Both implementations utilize a sample set of data captured during the I-210 Connected Corridors contract. The application is intended for use by experienced...

User Perceived Benefits with Navigation Systems

Commeignes, Hervé
1991

It has often been assumed that travel time savings are only beneficial to the users of route guidance and navigation systems. In particular, absolute travel time savings have been emphasized, but there has been little interest in relative time savings between equipped and unequipped vehicles. Part 2 of this report investigates to what extent relative travel time savings decrease as the percentage of equipped vehicles increases.In order to compensate for a possible decrease in relative time savings, some other potential services that can be provided by navigation systems are identified in...

California Transportation Management Centers Part 1. Assessment Of Existing Capabilities

Lo, Hong K.
Hall, Randolph W.
Windover, John R.
1993

Transportation Management Centers (TMCs) are focal points for monitoring and operating traffic management systems. As new technologies are developed through research in Intelligent-Vehicle- Highway Systems (IVHS), these TMCs will assume increasingly more importance as command and control centers for transportation operations. This study is aimed at developing visions for how the TMC of the future will exploit the capabilities of IVHS. Part 1 of this study, reported herein, is an assessment of existing TMC capabilities in the State of California. Part 2, to be reported later, will develop...

Relationships Among Urban Freeway Accidents, Traffic Flow, Weather and Lighting Conditions

Golob, Thomas F.
Recker, Wilfred W.
2001

Linear and nonlinear multivariate statistical analyses are applied to determine how the types of accidents that occur on heavily used freeways in Southern California are related to both the flow of traffic and weather and ambient lighting conditions. Traffic flow is measured in terms of time series of 30-second observations from inductive loop detectors in the vicinity of the accident prior to the time of its occurrence. Results indicate that the type of collision is strongly related to median traffic speed and to temporal variations in speed in the left and interior lanes. Hit-object...