Traffic Operations and Management

A Machine Vision Based System for Guiding Lane-change Maneuvers

Malik, Jitendra
Koller, Dieter
Luong, Tuan
1995

We propose a new approach for vision based longitudinal and lateral ve-hicle control which makes extensive use of binocular stereopsis. Longitudi-nal control - i.e. maintaining a safe, constant distance from the vehicle infront - is supported by detecting and measuring the distances to leadingvehicles using binocular stereo.A known camera geometry with respect tothe locally planar road is used to map the images of the road plane in thetwo camera views into alignment.Any significant residual image disparitythen indicates an object not lying in the road plane and hence a potentialobstacle....

Relieve Congestion and Conflicts Between Railroad and Light Rail Grade-Crossing Intersections

Zhang, Wei-Bin
Li, Meng
Wu, Guoyuan
Zhou, Kun
Bu, Fanping
2010

This report specifically summarizes the work that the PATH team has performed at this stage of Task Order 6407 in continuation of previous Task Order 5407. We have conducted an in-depth study of problems associated with grade crossingsfor this project.We started from the system design based on the proposed adaptive trolley signal priority (ATSP) system. The system is designed for large-scale field implementation of the ATSP system. It consists of three sub-systems: onboard sub-system, roadside control sub-system and central control sub-system. The system input and output diagram is based...

A Functional Architecture For Automated Highway Traffic Planning

Tsao, H. S. Jacob
1994

This report defines an architecture for Automated Highway System (AHS) capacity-optimizing traffic planning functions. It identifies major traffic planning functions useful for optimizing the capacity of one or more major AHS operating scenarios and organizes them in a robust architecture that is modular, hierarchical, complete, expandable and integratable.

Section-Related Measures of Traffic System Performance: Prototype Field Implementation

Ritchie, Stephen G.
Sun, Carlos
Oh, Seri
Oh, Cheol
2001

In this project (MOU 336),an initial phase of a field implementation was accomplished of the results of a previous research project (MOU 224),in which a vehicle reidentification algorithm based on loop signature analysis was developed using freeway traffic data.This algorithm was extended to non-freeway cases, initially using a section of 2-lane major arterial in cooperation with the City of Irvine,California.The technique was enhanced to address problems such as "irregularities " in vehicle signatures associated with trucks,tail-gating vehicles and erroneous counting of vehicles,with the...

Some Theoretical Aspects Of The Benefits Of En-route Vehicle Guidance (ervg)

Al-Deek, Haitham M.
Kanafani, Adib K.
1989

This paper concerns the benefits from vehicle route guidance in urban networks. We suppose that vehicle routes can be altered by En-Route Vehicle Guidance (ERVG) in such a way as to achieve system optimal assignment. Benefits are measured by the savings in total travel time for a given demand when comparing this assignment with the user equilibrium, which is assumed to occur in the absence of route guidance. A continuum approach is used to analyze some idealized corridors in which a freeway is superimposed over a dense grid of surface streets. Two cases are considered: in the first, the...

Enhanced AHS Safety Through the Integration of Vehicle Control and Communication

Hedrick, J. K.
Uchanski, M.
Xu, Q.
2003

In fiscal year 2002/2003 we finished the study of the effect of vehicle-vehicle/vehicle-roadside communication on the performance of adaptive cruise control (ACC) systems. Two simulation studies were finished. The first is a single ACC vehicle simulation using MATLAB/SIMULINK. A cut-in scenario and a braking scenario are tested. Communication greatly saves control effort in the former scenario, while it has little effect in the latter. The other work simulates ACC controlled highway merging using SHIFT language. The results show the beneficial effects of communication in terms of the...

The Cell Transmission Model. Part I: A Simple Dynamic Representation Of Highway Traffic

Daganzo, Carlos
1993

This paper presents a simple representation of traffic on a highway with a single entrance and exit. The representation can be used to predict traffic's evolution over time and space, including transient phenomena such as the building, propagation and dissipation of queues. The easy-to-solve difference equations used to predict traffic's evolution are shown to be the discrete analog of the differential equations arising from a special case of the hydrodynamic model of traffic flow. The proposed method automatically generates appropriate changes in density at locations where the...

Feasibility Study Of Advanced Technology Hov Systems: Volume 4: Implementation Of Lateral Control Systems In Transitways

Chira-chavala, Ted
Zhang, W. B.
Walker, J.
Javandel, F.
Demsetz, L.
1992

This study investigates issues concerning the implementation and impacts of lateral guidance/control systems and the phased implementation of these systems in exclusive-access High Occupancy Vehicle (HOV) lanes. The study is divided into 5 volumes. The objectives of each volume are as follows: Vol. 1: identify strategies for early deployment of longitudinal control technologies on the highway, and to evaluate potential impacts of these strategies on traffic operation, highway capacity, and traffic accidents. Vol. 2A: assess the feasibility of early deployment of Roadway Powered Electric...

Intelligent Cruise Control System Design Based on a Traffic Flow Specification

Swaroop, D.
Huandra, R.
1999

This paper investigates the problem of designing an Intelligent Cruise Control (ICC) algorithm for automated vehicles. An ICC algorithm, if implemented by every vehicle in the traffic, must guarantee that the density disturbances attenuate as they propagate up stream. Such a desirable property of the traffic is dependent on the spacing policy employed by automated vehicles and on the availability of information required to synthesize a string stable control law consistent with the employed spacing policy. The first part of the paper is concerned with the design of a spacing policy and the...

Integrated Roadway/Adaptive Cruise Control System: Safety, Performance, Environmental and Near Term Deployment Considerations

Ioannou, Petros
Wang, Yun
Chang, Hwan
2007

In this project, we present the design, analysis and performance evaluation of the Integrated Roadway/Adaptive Cruise Control System (IRAC) proposed in Task Order (TO) 4242 and studied further in the continuation of TO4242 under TO5501. The IRAC system is a highway traffic control system which integrates ramp metering strategies and a speed control strategy by taking into account highway to vehicle communication, and adaptive cruise control (ACC) system technologies on board of the vehicles. The IRAC system closes the loop of an almost open loop highway traffic system by controlling both...