Safety

WTRP-Wireless Token Ring Protocol

Ergen, Mustafa
2002

WTRP (Wireless Token Ring Protocol) is a medium access control (MAC) protocol for wireless networks. The MAC protocol through which mobile stations can share a common broadcast channel is essential in wireless networks. In a IEEE 802.11 network, the contention among stations is not homogeneous due to the existence of hidden terminals, partially connected network topology, and random access. Consequently, quality of service (QoS) is not provided. WTRP supports guaranteed QoS in terms of bounded latency and reserved bandwidth which are crucial real time constraints of the applications. WTRP...

Light Rail System Safety Improvements Using ITS Technologies

Chira-chavala, Ted
Coifman, Ben
Empey, Dan
Hansen, Mark
Lechner, Ed
Porter, Chris
1997

This report describes research which studied identifying and analyzing the effectiveness of countermeasures designed to reduce light rail crashes. Focus is in collisions with road vehicles at intersections. The light rail system for the Santa Clara County Transportation Agency in California served as the focus of the study.

Collision Avoidance Analysis for Lane Changing and Merging

Jula, Hossein
Kosmatopoulos, Elias B.
Ioannou, Petros A.
1999

One of the riskiest maneuvers that a driver has to perform in a conventional highway system is tomerge into the traffic and/or to perform a lane changing maneuver. Lane changing/mergingcollisions are responsible for one-tenth of all crash-caused traffic delays often resulting incongestion. Traffic delays and congestion, in general, increases travel time and has a negativeeconomic impact.In this paper, we analyze the kinematics of the vehicles involved in a lane changing/mergingmaneuver, and study the conditions under which lane changing/merging crashes can be avoided.That is, given a...

Quantifying the Performance of Countermeasures for Collision Concentration Related to Ramp/Freeway Mainline Junctions

Lee, Joon ho, PhD
Chan, Ching-Yao, PhD
Ragland, David R., PhD
2009

This study performed before-and-after analyses (comparisons of collisions before and after the construction of auxiliary lanes) on collision rate at nine study sites in California in order to achieve two objectives: (i) to estimate the freeway Crash/Collision Reduction Factor (CRF) for auxiliary lanes, and (ii) to develop design guidelines for the construction of auxiliary lanes. Findings indicate that on average, collision rates decreased by 17.3 percent at nine study sites. The study also found that after construction of auxiliary lanes at two study sites, collision rates increased when...

Platoon Collision Dynamics And Emergency Maneuvering IV: Intra-platoon Collision Behavior And A New Control Approach For Platoon Operation During Vehicle Exit/entry - Final Report

Tongue, Benson H.
Yang, Yean-tzong
1994

This report examines platoon behavior during non-nominal operations, most especially due to emergency braking. Three main topics are discussed: multiple-collision wave propagation effects for homogeneous platoons with and without lead vehicle information, intra-platoon collision behavior of non-homogeneous platoons during emergency operations, and a new control approach for platoon operations during vehicle exit/entry.

The Naturalistic Driver Model: Development, Integration, and Verification of Lane Change Maneuver, Driver Emergency and Impairment Modules: Final Report

Cody, Delphine
Tan, Swekuang
2009

This report describes the development of a driver model from a Human Science perspective, with the goal of integrating this model into a simulation environment supporting the design and support of Intelligent Transportation Systems. It also provides a discussion regarding the challenges faced in such an enterprise, concluding with a discussion concerning the need to develop a driver simulator.

Implementation of Advanced Techniques for Automated Freeway Incident Detection

Abdulhai, Baher
Ritchie, Stephen G.
Iyer, Mahadevan
1999

A significant body of research on advanced techniques for automated freeway incident detection has been conducted at the University of California, Irvine (UCI). Such advanced pattern recognition techniques as artificial neural networks (ANNs) have been thoroughly investigated and their potential superiority to other techniques has been demonstrated. Of the investigated ANN architectures, two have shown the best potential for real-time implementation: namely, the Probabilistic Neural Network (PNN), (Abdulhai and Ritchie 1997), and the Multi-Layer-Feed-Forward Neural Network (MLF), (Cheu and...

Community-Based Pedestrian Safety Training in Virtual Reality: A Pragmatic Trial

Schwebel, DC
Combs, T
Rodriguez, D
Severson, J
Sisiopiku, V
2016

Child pedestrian injuries are a leading cause of mortality and morbidity across the United States and the world. Repeated practice at the cognitive-perceptual task of crossing a street may lead to safer pedestrian behavior. Virtual reality offers a unique opportunity for repeated practice without the risk of actual injury. This study conducted a pre-post within-subjects trial of training children in pedestrian safety using a semi-mobile, semi-immersive virtual pedestrian environment placed at schools and community centers. Pedestrian safety skills among a group of 44 seven- and eight...

Evaluation of Feasibility of UAV Technologies for Remote Surveying BART Rail Systems

2018

Routine inspection and monitoring of railway tracks and facilities is an important task to ensure operational safety. The existing standard manual and rail vehicle based investigation are substantially time consuming and inaccurate. UAV-based autonomous monitoring and inspection technology has shown great potential in many fields and industries but it has been rarely explored in railway transit systems. UC Berkeley California Partners for Advanced Transportation Technologies   (PATH) in partnership with Bay Area Rapid Transit (BART) investigated  the application...

Power System Reliability for Precision Docking and Electronic Guidance Systems

Nesgaard, Carsten
Sanders, Seth
Zhang, Wei-Bin
2005

This final reports the fault analysis of precision docking system and safety design of the safety critical elements for precision docking system. The report includes three Parts, including:Part I provides a description of the Precision Docking System and reports analysis for fault diagnosis and safety design of automated steering controller and Electronic Control Unit (ECU) for steering actuator. It also reports a demonstration PATH conducted during the National Intelligent Vehicle Initiative demonstration organized by the US Department of Transportation Joint Program Office.Part II report...