Safety

Models Of Vehicular Collision: Development And Simulation With Emphasis On Safety IV: An Improved Algorithm For Detecting Contact Between Vehicles

O'Reilly, Oliver M.
Papadopoulos, Panayiotis
Lo, Gwo-jeng
Varadi, Peter C.
1998

This report describes a procedure for detecting the geometry of the contact interface between vehicles. This technique uses a better approximation of the vehicle's shape and also preserves the advantage of the ellipsoidal model. This new model for the low relative velocity vehicular collision is based on a box model for the outer surface of the vehicle and is referred to as BM.

Issues In Fault Tolerant Control Of Vehicle Follower Systems

Hedrick, J. K.
Garg, V.
1994

The aim of this report is to study issues concerning fault detection and identification in vehicle follower control. The report discusses various potential fault modes among sensors, and actuators used in the vehicle following experiments in cars. It deals with issues of fault detection of sensors and actuators for vehicle following applications.

Safety Assessment of Advanced Vehicle Control and Safety Systems (AVCSS): A Case Study

Chan, Ching-Yao
Zhang, Wei-Bin
El Koursi, El Miloudi
Lemaire, Etienne
2001

Advanced Vehicle Control and Safety Systems (AVCSS) involve several safety critical functionssuch as vehicle longitudinal and lateral control. It is required that the system be able to prevent ormitigate hazardous conditions. The system must be capable of tolerating failures and, whenfailures are no longer tolerable, be fail-safe. In order to verify the safety of a system, anassessment or evaluation methodology must be developed and implemented prior toimplementation of new technologies such that errors in the processes of specification, design,development, and integration can be revealed...

Wireless Token Ring Protocol

Lee, Duke
2001

The Wireless Token Ring Protocol (WTRP) is a medium access control protocol for wireless networks in Intelligent Transportation Systems. It supports quality of service in terms of bounded latency and reserved bandwidth. WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions. It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time. It is a distributed protocol that supports many topologies since not all stations need to be connected to each...

A Handbook For Inter-vehicle Spacing In Vehicle Following (includes Disk)

Sun, Y.
Ioannou, P.
1995

In this paper, a general worst case stopping scenario for vehicle following is used to develop algorithms for generating the minimum safety spacing (MSS) for collision-free vehicle following. These algorithms are used to study the effects of vehicle characteristics and other parameters on the value of the MSS. Furthermore, a case is considered where the choice of a smaller value of inter-vehicle separation leads to a rear-end collision. The effects of the various parameters on the severity of collision by using a proposed algorithm are studied. The results and algorithms developed in this...

Conditions for Safe Deceleration of Strings of Vehicles

Lygeros, John
Lynch, Nancy
2000

A simple model for a string of vehicles is constructed. The model explicitly accounts for the possibility of repeated collisions between the vehicles in the string. Based on the model a notion of safety is formulated for the string. Necessary and sufficient conditions are presented that specify when a string of vehicles is safe while performing a simple emergency deceleration maneuver where all vehicles start decelerating at a fixed rate after some delay. The conditions are interpreted in terms of their implications for the safety of platoons of vehicles.

Effectiveness of VMS Using Empirical Loop Detector Data

Huo, Hong
Levinson, David
2006

This study employs traffic data and incident data from the Twin Cities of Minneapolis and St. Paul, Minnesota. The conclusion in this study provides guidance on making policy about investing in VMS systems.Few studies utilize empirical traffic data. They either use costly surveys or conduct traffic simulation, which are expensive and may not conform well to reality. This study uses empirical traffic flow and occupancy data on both mainline and ramps, collected every 30 seconds to estimate the effectiveness of VMS. The variation of diversion rate before and after warning messages is...

Feasibility Study Of Advanced Technology Hov Systems: Volume 1: Phased Implementation Of Longitudinal Control Systems

Chira-Chavala, Ted
Yoo, S. M.
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...

Augmented Speed Enforcement Project at UC Berkeley - Executive Summary

Chan, Ching-Yao
Gupta, Somak Datta
2015

In this project, a speed alert and augmented enforcement system (aSE) was developed with a combination of sensing, image processing and recognition, wireless communication. The system includes a speed camera that captures speeding vehicles, and a changeable message sign that displays speeder’s license plate number and measured speed, and a web page that allows police officers to monitor the incidence of violators traveling at excessive speeds. The aSE system was field tested for a work zone application on a rural highway. With data collected over multiple weeks, under a baseline scenario...

Development and Evaluation of Selected Mobility Applications for VII

Shladover, Steven E.
Lu, Xiao-Yun
Cody, Delphine
Nowakowski, Christopher
Qiu, Zhijun (Tony)
Chow, Andy
O’Connell, Jessica
Nienhuis, Jaap
Su, Dongyan
2010

This report describes the development of two of the three mobility applications that PATH is developing and evaluating under the sponsorship of the FHWA Exploratory Advanced Research Program, with cost share funding provided by PATH TO 6224. These applications are intended to use DSRC wireless communications among vehicles and between vehicles and the roadway infrastructure to improve mobility on limited-access highways. The first application combines ramp metering with variable speed limits to enhance control of traffic so that traffic flow breakdowns can be deferred or avoided at...