Traffic Operations and Management

Personalized Demand Responsive Transit Systems

Yim, Y. B.
Khattak, Asad J.
2000

An aging population in the US, low-density urban sprawl and the accessibility needs of certain groups (particularly disabled and aged) increasingly point to more flexible demand-responsive transit systems in the future. This paper describes the important aspects of a consumer-oriented Personalized Demand Responsive Transit (PDRT) service. The system will provide services to the traveling public for journeys to work and for journeys to other destinations. A PDRT that responds to the travelers' needs and takes advantage of the emerging advanced public transportation technologies to increase...

Incident Management: Process Analysis And Improvement Phase 1: Review Of Procedures

Hall, Randolph
Mehta, Yatrik
1998

This working paper examines the process for managing incidents on highways, as it is applied in Los Angeles County. The examination is based on interviews with various agencies, including law enforcement, state highway department, coroners office, and LA County MTA Freeway Service Patrol, along with direct observation through ride-alongs. Follow-up work will quantify the benefits of improved incident management, through analysis of freeway performance and response characteristics during incidents.

Orange County Transit/traffic Management Integration And Traveler Information Project: Evaluation Plan

Hall, R.
Hickman, M.
1996

This document focuses on a Field Operational Test (FOT) to develop an integrated information system for transit and traffic management and for traveler information that relies on Global Positioning System (GPS) equipped buses as probe vehicles. The document provides the evaluation plan for the FOT. The plan covers three principal elements: 1) Institutional, TMC Operator and Bus Operator, 2) Public Knowledge and Perceptions, and 3) System performance. The document provides an overall evaluation framework that describes how the evaluation elements will assess project objectives. In addition...

Ideal Dynamic User-Optimal Route Choice: A Link-Based Variational Inequality Formulation

Ran, Bin
Boyce, David E.
1995

The ideal dynamic user-optimal (DUO) route choice problem is to determine vehicle flows on each link at each instant of time resulting from drivers using actual minimal-time routes. Actual route time is the travel time incurred while driving along the route. In a previous paper, we presented a route-based optimal control model for the ideal DUO route choice problem. However, this model is not appropriate for largescale transportation networks because some degree of route enumeration is necessary to solve the model. In this paper, we first present the traffic network constraints and link-...

An Enhancement to Speed Estimation with Single Loops

Lin, Wei-Hua
Dahlgren, Joy
Huo, Hong
2003

Traffic data from single loop detectors are one of the dominant data sources widely used in many traffic operation centers and traveler information systems. Speed estimation from single loop detectors is mainly based on occupancy data, a conversion factor from occupancy to density (which is related to vehicle length), and the assumed relationship between flow, speed, and density. This paper investigates the discrepancy between the speed estimated with single loops and the speed measured directly from double loops. It was found that the inaccuracy of speed estimation with single loops is...

Advanced Coordinated Traffic Responsive Ramp Metering Strategies

Bogenberger, Klaus
May, Adolf D.
1999

This report introduces different coordinated traffic responsive ramp control algorithms, implemented or not-implemented, but based on promising new mathematical techniques. A total of 17 different ramp metering approaches is described. For the already implemented algorithms, the historical background, the network, the algorithm and the main references are described. The proposed ramp control approaches are briefly described and the literature references are included. Two possible directions of ramp metering for the future are qualitatively described. Based on the literature review, online...

Adaptive Signal Control System with On-line Performance Measure for Single Intersection

Liu, Henry X.
Oh, Jun-Seok
Recker, Will
2002

This paper introduces an adaptive signal control system utilizing an on-line signal performance measure. Unlike conventional signal control systems, the proposed method employs real-time delay estimation and an on-line signal timing update algorithm. As a signal performance measure, intersection delay for each phase is measured in real-time via an advanced surveillance system that re-identifies individual vehicles both at upstream and downstream stations using vehicle waveforms obtained from advanced inductive loop detectors. In each cycle, the signal timing plan is optimized based on the...

Towards a Technology Assessment of Highway Navigation and Route Guidance

Kanafani, Adib
1987

This paper is intended as a first look at the required assessment of technology. It is preliminary in the sense that it attempts to identify the issues and to identify some aspects of technology assessment that are needed to deal with them. It's aim is to raise some of the fundamental questions that arise in connection with the evaluation of this technology, and to suggest some further work for dealing with them. A more extensive research plan for looking at the various aspects of automobile navigation is to be found in Gosling [1988].

Vehicles As Probes

Sanwal, Kumud K.
Walrand, Jean
1995

In this paper, the authors discuss the use of vehicles moving in traffic as probes that provide data for estimation and prediction of traffic behavior. The probe vehicles can report data on their speeds, locations, or travel times which can be used by an algorithm that updates estimates of traffic state and makes predictions for the future. The authors address some of the key issues involved in the design of such a traffic monitoring system.

Modernization of Center-to-Center Data Communication Standards: Gap Analysis Technical Memorandum

Peterson, Brian
2021

This document provides a gap analysis based on three previous technical memorandums delivered as part of this project, including a review of the Traffic Management Data Dictionary (TMDD) standard, a review of current and future transportation needs, and a review of the state of the art in technology and systems development. The intention of this document is to provide a review of this standard for transmission of data between traffic management centers (TMCs), with explicit commentary on usability of the standard with specific examples based on its implementation in the Caltrans I-210...