PATH

Simulation of IVHS on the Santa Monica Freeway Corridor Using the INTEGRATION Model. Phase 2: Preliminary ATIS and ATMS Experiments

Gardes, Yonnel
May, Adolf D.
1993

The general objective of the project is to investigate and quantify the likely benefits of implementing various ATMS and ATlS control strategies on the real-life Santa Monica freeway corridor in Los Angeles.The different strategies to be tested in Phase 2 include freeway ramp metering, real-time traffic signal optimization, route guidance systems, and combinations of these strategies. Investigations of different strategies are performed for the same network conditions (portion of the Santa Monica freeway corridor previously coded in Phase 1) and under the same demand level (typical morning...

Trav Info Evaluation Traveler Response Element: Trav Info 817-1717 Caller Study Phase 1 Results

Yim, Youngbin
Hall, Randoph
Koo, Ronald
Miller, Mark A.
1998

This paper presents a discussion on how traffic information is obtained and how the congestion of a major freeway affects travel behavior. It reports on survey results of commuters affected by two highway incidents south of San Francisco. The survey collected information on travel behavior, how the traffic information was obtained, and how it influenced route, model of travel and departure time. Results of the surveys suggest that travel behavior is largely unaffected by individual incidents of congestion. The study is also one of several designed to provide an assessment of the impact of...

Research And Testing For Its Deployment And Operation

Weissenberger, Stein
Dahlgren, Joy
Hickman, Mark
Lo, Hong
1996

In this paper, the authors, although agreeing that deployment is the ultimate goal of Intelligent Transportation Systems (ITS) research and funding, believe that there is not sufficient knowledge of how, why and when to deploy specific ITS functions They contend that continued research and testing (R &T) is still necessary to assure effective future deployment. The article identifies critical needs for R & T and is based to a large degree on the authors' experience in the California PATH research program.

BTS (Version 1 .1) - Bottleneck Traffic Simulator User’s Manual

Lin, Wei Hua
Hall, Randolph W.
1991

BTS can be used to evaluate a variety of changes in highway design to improve bottlenecks, such as: (1) addition of highway lanes, (2) addition of automated or HOV lanes, or (3) incident management strategies to reduce the frequency, duration and magnitude of incidents. BTS can also be used to project future highway conditions as baselevel traffic grows or driver behavior changes.The new version of BTS was enhanced to include incident dependencies, variable weather conditions, reneging, and randomly varying traffic volumes. As of yet, BTS is not capable of analyzing highway performance on...

Identifying the Onset of Congestion Rapidly with Existing Traffic Detectors

Coifman, Benjamin
1999

From an operations standpoint, the most important task of a traffic surveillance system is determining reliably whether the facility is free flowing or congested. The second most important task is responding rapidly when the facility becomes congested. Other tasks, such as quantifying the magnitude of congestion, are desirable, but tertiary. To address the first two tasks, this paper presents a new approach for traffic surveillance using existing detectors. Rather than expending a considerable effort to detect congested conditions, the research employs a relatively simple strategy to look...

The Cell Transmission Model: Network Traffic

Daganzo, Carlos
1994

This paper shows how the evolution of multicommodity traffic flows over complex networks can be predicted over time, based on a simple macroscopic computer representation of traffic flow that is consistent with the kinematic wave theory under all traffic conditions. After a brief review of the basic model for one link, the paper describes how three-legged junctions can be modeled. It then introduces a numerical procedure for networks, assuming that a time-varying origin-destination table is given and that the proportion of turns at every junction is known. These assumptions are reasonable...

Design, Fabrication and Calibration of a Vehicle Tow Bar for Platoon Drag Measurements: A Working Report

Hong, P.
Browand, F.
Marcu, B.
1997

A longitudinal stability model for a 2 vehicle platoon yields a pair of linearly coupled equations that model the dynamics of the tow bar and the vehicles. Using reasonable approximations, the vehicle separation distance obeys a second order non-linear differential equation with constant coeficients. Spring force and damping are provided by a special shock absorber link. The towbar linkage can be made to serve as a low pass mechanical system. The design spring constant of 60 1bfAn and a damping rate of 200 lbf/ft/sec yield a low-pass system with sufficient damping and a cut of frequency of...

Travinfor Evaluation: Value Added Reseller (var) Study Phase 1 Results

Loukakos, D.
Hall, R.
Weissenberger, S.
Yim, Y. B.
1996

TravInfo is a Field Operational Test (FOT) in advanced traveler information systems (ATIS) for the San Francisco Bay Area sponsored by the Federal Highway Administration (FHWA). The project involves a public/private partnership which seeks to compile, integrate and broadly disseminate timely and accurate multi-modal traveler information through commercial products and services. This working paper is part of the Technology Element of the TravInfo evaluation. It presents the results of the "before" wave of the Value-Added-Reseller (VAR) study, in which 17 TravInfo registered VARs and 16 non-...

On-line Traffic Signal Control Scheme with Real-time Delay Estimation Technology

Liu, Henry X.
Oh, Jun S.
Oh, Seri
Chu, Liany
Recker, Will
2001

This paper presents an on-line signal control scheme integrated with the real-time intersection delay estimation technology. The primary goal of this study is to design a complementary optimization module to the existing controller to minimize the total delay experienced by traffic and improve the system performance at the signalized intersections. This paper proposes a feedback control algorithm that optimizes the signal timing plan based on delay estimated via vehicle re-identification technology. Main thrust of the algorithm is on-line control capability utilizing direct delay measures...

A Multi-channel VANET Providing Concurrent Safety and Commercial Services

Mak, Tony K.
Laberteaux, Kenneth P.
Sengupta, Raja
2005

One of the key goals of a vehicular ad-hoc network (VANET) is providing sufficient quality of service (QoS) for real-time safety applications while concurrently supporting commercial services. This paper proposes a multi-channel wireless communication architecture and protocol for the scenario where commercial services are provided by roadside infrastructure. This solution extends the IEEE 802.11 wireless LAN protocol to schedule periodic safety messages in a "safety channel". It explicitly supports concurrent non-time-critical communications in separate, non-safety "service channels"....