Safety

Expedited Crash Investigation - With Use of Technologies for Documentation and Processing

Chan, Ching-Yao
Lian, Thang
Ko, Jeff
2007

The mobility and efficiency of California highways are impeded by the recurrent and non-recurrent congestion on a daily basis. Roadway incidents, especially collisions, often result in traffic congestion and travel delays. This project is initiated to explore the use of technologies that will potentially bring direct and immediate benefits to the law enforcement officers and other personnel who are involved in the handling of collision sites and subsequent investigations. The work carried out in this project includes three major components: (1) The experimentation of integrated vehicular...

Freeway Safety as a Function of Traffic Flow: The FITS Tool for Evaluating ATMS Operations

Golob, Thomas F.
Recker, Wilfred W.
Alvarez, Veronica
2002

Understanding the benefits of improved traffic flow (reduced congestion) is critical to the assessment of investments in infrastructure or traffic management and control. Improved flow should lead to reductions in travel time, vehicle emissions, fuel usage, psychological stress on drivers, and improved safety. However, the manner in which safety is improved by smoothing traffic flow is not well understood. The documented research is aimed at shedding light on the complex relationships between traffic flow and traffic accidents (crashes).

Intelligent Diagnosis Based On Validated And Fused Data For Relilability And Safety Enhancement Of Automated Vehicles In An IVHS

Agogino, Alice
Chao, Susan
Goebel, Kai
Alag, Satnam
Cammon, Bradly
Wang, Jiangxin
1998

Vehicles in an IVHS system rely heavily on information obtained from sensors. So far, most control systems make the implicit assumption that sensor information is always correct. However, in reality, sensor information is always corrupted to some degree by noise which varies with operating conditions, environmental conditions, and other factors. In addition, sensors can fail due to a variety of reasons. To overcome these shortcomings, sensor validation is needed to assess the integrity of the sensor information and adjust or correct as appropriate. In the presence of redundant information...

A System Review of Magnetic Sensing System for Ground Vehicle Control and Guidance

Chan, Ching-yao
2002

This report contains research results of studies on magnetic marker systems that are used as a posi-tionreference system for Advanced Vehicle Control and Safety Systems. Effects of external objectsand earth background fields on such systems are investigated with experimental measurements inPart I. The results show that signal processing techniques must be adopted in field applications toimprove the accuracy and robustness of sensing algorithms. Part II of the report contains experimen-talresults from an evaluation study of PATH marker system and 3M Tape system. The objective isto identify...

Coordinating Automated Vehicles via Communication

Bana, Soheila Vahdati
2001

This dissertation addresses the coordination of automated vehicles in an Auto- mated Highway System (AHS). Tra c in an AHS is organized as tightly spaced platoons to increase road capacity and safety. Vehicles in AHS are automated and their safe interaction is the subject of this research. This dissertation discusses issues in the design and imple- mentation of a controller for automated vehicles that coordinates the interaction between vehicles. We rst de ne a formalism for safe interaction of automated vehicles and then design a controller algorithm for an individual vehicle that...

Incident Management: Process Analysis and Improvement

Hall, Randolph W.
2001

This is the final report for the project Incident Management:Process Analysis and Improvement.The report summarizes findings from three earlier working papers (1998-31,2000-14 and 2000-15)completed under this project, and provides additional analysis on specific scenarios. This study highlights the importance of the following principles: 1)Response units should be adequate in number to handle anticipated demand. 2)Response units should be strategically located to minimize maximum response times. 3)Especially during busy periods,response units should not be dispatched over long distances.It...

Evaluating Wireless Broadband and System At California Safety Roadside Rest Areas

Finson, Rachel S.
Lidicker, Jeffrey
Phan, Cynthia
Rodier, Caroline
2008

To meet the demand for Internet access by the traveling public, the California Department of Transportation (Caltrans) launched a field operational test of wireless Internet access (WiFi) at two Safety Roadside Rest Areas (SRRAs), Phillip S. Raine and Enoch Christoffersen, along State Route (SR) 99 in July 2007. In this report, researchers evaluate the potential of WiFi at California’s SRRAs in order to make recommendations for future public agency participation in SRRA WiFi partnerships. A number of methods were used to gain insight into the potential of WiFi at SRRAs including (1) expert...

Integrated Construction Zone Traffic Management

Zhang, Michael
Shen, Wei
Nie, Yu
Ma, Jingtao
2008

Nonrecurrent traffic congestion caused by construction work constitutes a large proportion of the traffic congestion on highways. In TO 5300, we developed a comprehensive work zone traffic impact assessment procedure using a series of state-of-the-art dynamic network analysis tools as building blocks. This procedure is then implemented into a work zone traffic impact assessment software package called NetZone. This software package is capable of estimating time-dependent travel demand based on link counts, estimating demand diversion in response to work zone delay and various traffic...

Ad-hoc Medium Access Control Protocol Design and Analysis for Vehicle Safety Communications

Sengupta, Raja
Xu, Qing
Mak, Tony
Ko, Jeff
2004

This paper studies the design of ad-hoc Medium Access Control (MAC) protocols for a vehicle or the roadside to send safety messages to other vehicles. Such a protocol is needed by Advanced Vehicle Safety Systems (AVSS) and the national Dedicated Short Range Communications (DSRC) architecture. The problem is formulated to meet the communication requirements of vehicle safety applications and the DSRC multi-channel operation model. We propose several ah-hoc protocols, all based on the principles of repetition coding. Analytical bounds of the protocols' performance are derived. Simulations...

Assessing Benefits of Coordination on Safety in Automated Highway Systems

Choi, Woosuk
Swaroop, Darbha
2001

In this report, we present a methodology for assessing the benefits of different vehicle coordination strategies on the safety of a platoon during emergency braking. One can say that a coordinated braking strategy B is more beneficial than a strategy, if strategy B leads to a larger reduction in the probability of a collision, the expected number of collisions, and the expected relative velocity at impact as compared to strategy .We consider an emergency braking scenario, in which the lead vehicle brakes at its maximum capability and the following vehicles brake while obeying a vehicle...