PATH

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.

Incident Dispatching, Clearance and Delay

Hall, Randolph
2000

This report models response times and delays for highway incidents, according for spacing between interchanges and the time penalty for changing directions, enabling a response vehicle to reach an incident on the opposite side of the highway. A fundamental question in dispatching incident crews is whether to send the closest vehicle that is currently available or to wait for another to become available that is even closer. Waiting for a closer one is advantageous because service time is effectively reduced, adding to capacity and providing stability at higher levels of utilization. But...

Studies of Vehicle Collisions-A Documentation of the Simulation Codes: SMAC (Simulation Model of Automobile Collisions) Update 1

Chan, Ching-Yao
1999

This document describes part of the work conducted under MOU252 and MOU324, related to the studies of vehicle collisions in vehicle-following operations. This working paper is a detailed documentation of a computer program that is the core element of the simulation tools for vehicle collision dynamics. The program, SMAC (Simulation Model of Automobile Collisions), and its PC-platform version EDSMAC have been used extensively in recent work at PATH to investigate the consequences of vehicle collisions and the effects of vehicle-following parameters on collisions. A copy of the source codes...

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...

Daily Activity and Multimodal Travel Planner: Phase 1 Report

Kitamura, Ryuichi
Chen, Cynthia
1998

Travel constitutes an integral part of our daily life. Only by traveling are we able to engage in a variety of activities at different locations. Since the extension of our movement is restricted by the amount of time that is available and the speed with which we can move, it is important that our travel be efficiently organized such that the time resource can be best utilized to engage in activities in an efficient manner. One approach to achieving this is to choose less congested and faster routes. The use of in-vehicle advanced traveler information systems (ATIS) for this purpose has...

Traffic Measurement and Vehicle Classification with a Single Magnetic Sensor

Cheung, Sing Yiu
Coleri, Sinem
Dundar, Baris
Ganesh, Sumitra
Tan, Chin-Woo
Varaiya, Pravin
2004

Wireless magnetic sensor networks offer a very attractive, low-cost alternative to inductive loops for traffic measurement in freeways and at intersections. In addition to vehicle count, occupancy and speed, the sensors yield traffic information (such as vehicle classification) that cannot be obtained from loop data. Because such networks can be deployed in a very short time, they can also be used (and reused) for temporary traffic measurement. This paper reports the detection capabilities of magnetic sensors, based on two field experiments. The first experiment collected a two-hour trace...