PATH

Vehicle Longitudinal Control Test

Choi, Sei-bum
1994

This report evaluates several engine torque control laws for longitudinal vehicle control. The control laws are implemented and tested on a low speed test track. The test results and analysis show that engine manifold air-dynamics can not be neglected especially at low engine speed. An ultrasonic distance sensor is evaluated under several road conditions. Two vehicle tracking control is tested using the ultrasonic sensor and radio transceivers.

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...

New Aggregation Strategies to Improve Velocity Estimation from Single Loop Detectors

Coifman, Benjamin
Lee, Zu-Hsu
2000

Loop detectors are the preeminent vehicle detector for freeway traffic surveillance. Although single loops have been used for decades, debate continues on how to interpret the measurements. Many researchers have sought better estimates of velocity from single loops. The preceding work has emphasized post-processing techniques. Although rarely noted, these techniques effectively seek to reduce the bias due to long vehicles in measured occupancy and flow. This paper presents a different approach, using a new aggregation methodology to estimate velocity and reduce the impact of long vehicles...

Estimation Of Travel Time Distribution And Detection Of Incidents Based On Automatic Vehicle Classificatin

Anatharam, V.
1998

We study the problem of travel time estimation along a section of a freeway based on data derived from vehicle detectors at multiple locations. We pose the problem as one of pattern recognition. We derive algorithms that aim to recognize patterns which persist between the error-prone upstream detector samples and the error-prone downstream detector samples. We describe how these can allow us to estimate the distribution of the travel time between these detector locations. The most promising algorithm derived in this research is a dynamic programming based algorithm based on sequence...

Institutional Aspects of Bus Rapid Transit – A Macroscopic Examination

Miller, Mark A.
Buckley, Stephen M.
2000

This report investigated the institutional aspects of Bus Rapid Transit through a macroscopic examination of relevant issues ascertained through a literature review, a series of project team brainstorming meetings, and input from members of the Federal Transit Administration’s Bus Rapid Transit staff. The literature review provided insight into the history of Bus Rapid Transit concepts ranging from very early research in the United States in the late 1950s, continuing with dual mode systems and early busways in the 1960s and 1970s, international experiences in Latin America and Canada, and...

Productivity Benefits and Cost Efficiencies from ITS Applications to Public Transit: The Evaluation of AVL

Gillen, David
Chang, Elva
Johnson, Doug
2000

The research reported in this document uses Total Factor Productivity (TFP) techniques, with which we develop measures of productivity performance of public transit systems of varying sizes and locations, and use this baseline to examine the potential contribution of alternative ITS applications. TFP aggregates outputs on the basis of their revenue contribution and inputs on the basis of their relative importance to total costs to calculate the overall firm productivity as a function of these quantities. The focus of this research was how the opportunities for improving efficiency via AVL...

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...

AHS Deployment: A Preliminary Assessment of Uncertainties

Hall, Randolph W.
Tsao, H.-S. Jacob
1994

This paper provides a preliminary assessment of uncertainties, both technical and institutional, associated with the deployment of Automated Highway Systems (AHS). Seven issues are addressed, concerning whether: (1) People use AHS, ( 2 ) Auto makers manufacture equipped vehicles, (3) Government builds AHS roadways, (4)Highways can evolve, ( 5 ) Interest groups do not obstruct, (6) Performance is adequate, and (7) Technology is feasible. For each issue, a table is provided that lists some of the more critical uncertainties.

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...