PATH

Caltrans TOPS Evaluation: Assessing the Net Benefits of ITS Applications

Gillen, David
2001

This report describes the outcome of a set of experiments undertaken to assess the net benefits of ITS applications in a stylized urban and near urban highway network.

Individual Vehicle Speed Estimation Using Single Loop Inductive Waveforms

Sun, Carlos
Ritchie, Stephen G.
1999

Travel time is the reciprocal of speed and is a useful measure of road congestion and traffic system performance. Travel time is also a basic traffic variable that is used in many Intelligent Transportation System (ITS) strategies such as route guidance, incident detection, and traveler information systems. Previously, speeds were mainly acquired from double inductive loops configured as speed traps, since single loop speed estimates based on assumptions of a constant vehicle length were inaccurate. However, more accurate measurements of speed can now be accomplished with single loops by...

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...

Travinfo Evaluation: Traveler Response Element Broad Area Study

Yim, Y. B.
Hall, R.
Weissenberger, S.
1997

This paper presents the preliminary findings of a first wave Broad Area survey, administered in November 1995, of the TravInfo Field Operation Test in the San Francisco Bay Area. The purpose of the survey was to define baseline attitudes, opinions and travel behavior of travelers for assessment of the general impact of TravInfo. Questions focused on trip characteristics, acquisition patterns of information, effects of traffic information on travel behavior and the demographic profiles of Bay Area travelers.

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.

The Los Angeles Freeway Service Patrol (fsp) Evaluation: Study Methodology And Preliminary Findings

1997

This paper presents a methodology to evaluate a benefit-to-cost ratio effectiveness of the Freeway Service Patrol in a freeway section in Los Angeles. The methodology addresses the process of estimating incident delay using probe vehicles and the lack of "before" data.

Truck Scheduling for Ground to Air Connectivity: Final Report

Hall, Randolph W.
Lo, Shih-Che
2002

A critical link in the overnight package business is the on-time arrival of trucks at airport terminals. Truck delays can delay the package sorting and transfer process, which can in turn delay aircraft departures from the local terminal, as well as aircraft departures from hub terminals that depend on timely aircraft arrivals. This report models the airport terminal as a queueing process with random bulk arrivals. The models have been implemented in a web-based decision support tool (Truck to Air Dispatch, TAD, available at the website ger309-pc16.usc.edu), which provides real-time...

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...

Analysis, Design, And Evaluation Of AVCS For Heavy-duty Vehicles: Phase 1 Report

Yanakiev, Diana
Kanellakopoulos, Ioannis
1995

This report addresses the problem of automation of heavy-duty vehicles. After a brief description of the dynamic model used in the design and simulations, the authors develop nonlinear controllers with adaptation, first for speed control and then for vehicle follower longitudinal control. Both autonomous operation as well as intervehicle communication are considered, and the performance of the controllers in several different scenarios through simulation are evaluated.