Traffic Operations and Management

Travel Time Estimation on the San Francisco Bay Area Network Using Cellular Phones as Probes

Ygnace, Jean-Luc
Drane, Chris
Yim, Y. B.
de Lacvivier, Renaud
2000

Current traffic travel time estimates are largely based on road sensors embedded in the pavement. Today technical developments in cellular positioning and the spread of wireless phones provide the opportunity to track cell phone equipped drivers as traffic probes. The Federal Communication Commission Phase II mandate for Enhanced-911 (E-911) requires that wireless carriers must provide the location of a 911 wireless call by October 1, 2001 to the Public Safety Answering Point (PSAP), within approximately 125 meters, or under one-tenth of a mile in the majority of situations. The motivation...

Effect of Longitudinal Control on Capacity

Beji, Yousser
1987

This paper focuses on what benefits a longitudinal control system can be expected to render to the present highway system.There are three major reasons why longitudinal control should be expected to improve traffic flow and to reduce accidents.(1) It may permit higher traffic densities with uniform spacing forming an even distribution with increased travel speeds and consequently higher capacity.(2) It may reduce the rate of rear-end collisions that occur on urban freeways.(3) It can provide increased stability in traffic flow (shockwaves due to human response characteristics are the main...

PATH ATMIS State of the Research Annual Report Fiscal Year 1998 / 1999

Tam, Robert
1999

This report summarizes PATH ATMIS and Systems research for fiscal year 1998/1999. 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 also give a reader an overview of the entire program...

TMDD Standards Update Recommendations – Data Structures

Peterson, Brian
2023

This document provides a set of recommendations for modernization of the Traffic Management Data Dictionary (TMDD) (1), currently at version 3.1. These recommendations are based upon the following: Connected Corridors project experience; three previous technical memorandums provided under this project discussing the current and future state of transportation, the state of the supporting technology for information exchange, and a review of the TMDD standard; a gap analysis based on the three technical memorandums delivered as part of this project. The intention of this document is to inform...

Lateral Control Of Commuter Buses

Hingwe, Pushkar
Tomizuka, Masayoshi
1995

This report presents two approaches to the design of the lateral controllers for commuter buses based on Sliding Mode Control (SMC). The objective of the control is to track the lane centerline. The first controller uses the sensor output which is a combination of yaw and lateral error. The second controller achieves tracking objective by providing a yaw rate to the vehicle so as to keep the lateral error dynamics stable. The two controllers are compared by performing simulations for a range of parameters.

Incident Management with Advanced Traveller Information Systems

Al-Deek, Haitham
Kanafani, Adib
1991

Advanced Traveller Information Systems (ATIS) can be used to collect and disseminate dynamic information about travel times on highway links. One of the potential uses of these systems is to manage incidents. The objective of this research is to showunder what incident conditions is it relevant to provide real time traffic information to travellers.A model that uses graphical queueing techniques is utilized to define cases when ATIS is beneficial and cases when it is not, and to evaluate its benefits as measured by travel time savings. The model is applied to a simple road network with two...

Traffic Management Systems Performance Measurement: Working Paper #2

Banks, James H.
Kelly, Gregory
1997

Traffic Data System Improvement Plans were prepared for Caltrans Districts 1 1 (San Diego) and 12 (Orange County) as part of a research project on performance measurement for traffic management systems. The plans document data system objectives, data requirements, and existing data collection and management systems; evaluate the adequacy of existing systems; identify improvements and resource requirements; and document the districts’ priorities for action. Both districts have similar data systems, although Orange County’s is better developed. Both systems rely heavily on single-loop...

TravInfo Evaluation (Technology Element) Traveler Information Center (TIC) Study: Operator Response Time Analysis

Miller, Mark A.
Loukakos, Dimitri
2000

TravInfo (TM) is an advanced traveler information system for the San Francisco Bay Area that began operation in September 1996 under a public/private partnership. The public sector component centers on the Traveler Information Center (TIC), TravInfo (TM)'s information gathering, processing, and dissemination hub. For two years, until September 1998, TravInfo (TM) was a Field Operational Test (FOT) sponsored by the Federal Highway Administration. During the FOT, the TIC was evaluated. This report documents the analysis of operator response time. Response times remained stable throughout the...

Dynamic Traffic Assignment For Automated Highway Systems: A Two-lane Highway With Speed Constancy

Tsao, H. S. Jacob
1996

Dynamic traffic assignment through analytical modeling and optimization has been widely accepted by the IVHS R&D community as a promising traffic control tool for understanding and relieving traffic congestion on conventional highways and city streets. Due to the completely controlled nature of AHS traffic, dynamic assignment of AHS traffic is even more promising. One added dimension of complexity associated with AHS dynamic traffic assignment is lane assignment. Lane changes, for fully utilizing AHS capacity or for exiting, incur disturbances to and hence reduction of longitudinal...

Highway Electrification: An Exploration of Energy Supply Implications

Wang, Quanlu
Sperling, Daniel
1987

The objective of this preliminary report is to explore the energy supply opportunities and implications of electrifying highways. An important assumption in this report is that the technology and general cost structure for generating and storing electricity does not change significantly in the future. In other words, we ignore the possible use of super conductive materials to store electricity during off-peak times, which, if feasible, would greatly reduce average electricity costs. A future report will examine the opportunities and implications of breakthroughs in superconductivity.The...