Safety

Weaving Analysis, Evaluation and Refinement

Skabardonis, Alexander
Kim, Amy
2010

Weaving sections are common design elements on freeway facilities such as near ramps and freeway to-freeway connectors. When the traffic demands exceed the capacity at weaving areas congestion may occur, which affects the operation of the entire freeway section. Traffic operational problems also may exist at weaving areas even when traffic demands are less than capacity because of the complexity of vehicle interactions, resulting in poor level of service (LOS) and potential safety problems. Existing procedures for the design and analysis of freeway weaving sections have several...

The Effects of Truck Driver Wages and Working Conditions on Highway Safety: A Case Study

Rodriguez, DA
Rocha, M
Khattak, AJ
Belzer, MH
2006

The role that human capital and occupational factors play in influencing driver safety outcomes has gained increased attention from trucking firms and policy-makers. This paper examines the role of these factors, in addition to demographic factors, in influencing crash frequency at the driver level. A unique driver-level dataset from a large truckload firm collected over a period of 26 months is used for estimating regression models of crash counts. Based on estimates from a zero inflated Poisson regression model, results suggest that human capital and occupational factors, such as...

Models of Vehicular Collision: Development and Simulation with Emphasison Safety II: On the Modeling of Collision between Vehicles in a Platoon System

O'reilly, Oliver M.
Et. al.
1997

In this report, an algorithm for the detection of collision between two vehicles is presented. The mechanical models used for the vehicles are based on the theory of a Cosscrat point. Here, we find it convenient to establish the corresponding models using the theory of a psuedo-rigid body. This theory facilitates the development of our collision-detection algorithm. The report concludes with four examples of vehicular impact scenarios in order to illustrate the applicability of the proposed algorithm.

Seamless Travel: Measuring Bicycle and Pedestrian Activity in San Diego County and its Relationship to Land Use, Transportation, Safety, and Facility Type

Jones, Michael G.
Ryan, Sherry
Donlon, Jennifer
Ledbetter, Lauren
Ragland, David R.
Arnold, Lindsay
2010

This paper provides the data collection and research results for the Seamless Travel project. The Seamless Travel Project is a research project funded by Caltrans and managed by the University of California Traffic Safety Center, with David Ragland, PhD., as the Principal Investigator and Michael Jones as the Project Manager. The project is funded by Caltrans Division of Innovation and Research and is being conducted by the Traffic Safety Center of University of California Berkeley and Alta Planning + Design.Measuring bicycle and pedestrian activity is a key element to achieving the goals...

Workzone Safety Improvements through Enhanced Warning Signal Devices

Christianson, Kent
Greenhouse, Daniel
Cohn, Theodore
Kim, Roy Young
Chow, Christina
2008

The high incidence of accidents associated with work zones suggests that current warning lights and signals have been in need of improvement. In this project we have developed and tested an improved emergency warning light intended specifically for Caltrans work zone vehicles, and an enhanced rear warning light for shadow trucks, both intended to improve visibility and conspicuity, and to reduce reaction times for drivers approaching the work zone.

Transient Aerodynamic Effects on a Four-Car Platoon During Passing Maneuvers: Data Summary

Tsuei, L.
Hedrick, J. K.
Savas, O.
1999

In order to provide reliable control algorithms on PATH automated highway system, knowledge of the transient aerodynamic forces is important from the point of the controlla- bility of the platoon and individual vehicles. In a passing maneuver, the platoon members may experience severe aerodynamic forces and yaw moment when another vehicle overtakes. Similar phenomenon can be seen in our daily life as one car passes the other but much more complicated flow field is expected when the interaction involves in a multi-vehicle platoon. It is the purpose of this study to quantify the unsteady...

Safety Performance and Robustness of Heavy Vehicle AVCS

Taylor, R. Jemonde
Yih, Paul
Gerdes, J. Christen
2005

Dynamically, heavy trucks are inherently different than passenger cars. In addition to the increase rollover risk arising from an elevated center of gravity height, heavy trucks possess additional failure modes such as jackknifing and excessive trailer swing. As a response to these issues, significant research has been performed in the last three decades to establish safety metrics for heavy trucks based on dynamic testing. This research has had an impact on determining acceptable size and weight restrictions for heavy vehicles and on the actual design of heavy trucks for increased safety...

Safety Performance and Robustness of Heavy Vehicle AVCS

Yih, Paul
Satyan, Krishna
Gerdes, J. Christian
2003

Commercial heavy vehicle research at the California Partners for Advanced Transit and Highways (PATH) program has focused on the development of controllers for partially to fully automated driving environments. Safe performance of Advanced Vehicle Control Systems (AVCS) must be demonstrated for a wide range of operating conditions and truck configurations to avoid any one of the many failure modes-such as rollover or jackknifing-common to articulated heavy vehicles. For this purpose, a multi-body dynamic model of a tractor semitrailer has been developed using a commercially available...

Methods Of Analysis Of Ivhs Safety: Executive Summary

Hitchcock, Anthony
1992

This report presents the executive summary to a study on developing and demonstrating methods by which the safety of Intelligent Vehicle Highway Systems (IVHS) can be assured, assessed and evaluated. Safety considerations were studied for automated freeways, driver aids and copilots. Management and policy issues are briefly discussed in conclusion.

Rest Areas – Reducing Accidents Involving Driver Fatigue

Banerjee, Ipsita
Lee, Joon ho
Jang, Kitae
Pande, Swati
Ragland, David
2010

Rest areas are a countermeasure for fatigue; what role do they play in fatigue-related freeway collisions? The present study spatially evaluates fatigue collisions. In California, of 2,203,789 highway collisions recorded between 1995 and 2005, fatigue collisions accounted for 1.3% (‘strict’ definition of fatigue) and 9.7% (‘expanded’ definition). Collisions in the vicinity of rest areas were investigated using two different approaches: 1. 10-miles up/downstream of rest areas 2. Distance traveled from rest areasSample t-tests indicated that both fatigue and non-fatigue collisions decreased...