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Canton, ME, United States

Heath D.,AECOM Technology Corporation | Silvestri C.,Texas A&M University | Ray M.,Roadsafe LLC
Transportation Research Record

Recent improvements to occupant restraint systems, such as seat belts and airbags, have caused a shift in the injury profile that results from vehicle collisions from primarily upper body to primarily lower extremity injuries. Injuries of the knee-thigh-hip (KTH) region have been shown to be some of the most debilitating. This project used a finite element model of the KTH region to study injury. A parametric investigation was conducted; the finite element KTH was simulated as a vehicle occupant positioned to a range of precrash driving postures. Results indicated that timing between a significant rise in foot-floor and knee-bolster contact force affected knee kinematics and axial force absorbed by the KTH region. Findings also suggest that introducing a lag time between the respective contacts may decrease the likelihood of KTH bone injury. Source

Mongiardini M.,University of Nebraska - Lincoln | Ray M.H.,Roadsafe LLC | Plaxico C.A.,Roadsafe LLC
International Journal of Computer Applications in Technology

Assessing the level of match between two curves is a recurring operation in most scientific fields, which should be performed as objectively as possible. In this research, a computer programme was developed to quantitatively compare two curves through various metrics. A series of options were implemented to appropriately preprocess the curves before being compared, with both the input and preprocessing operations managed through intuitive graphical user interfaces (GUIs). The reliability of the objective scores computed by the programme was investigated by analysing the results obtained from the comparison of two pairs of curves against the subjective judgement of a group of experts. Also, as an example of application for the validation of a numerical model, an acceleration curve from a vehicular full-scale crash test was compared with the corresponding time history obtained from a finite element (FE) analysis. Both the comparison with the subjective expert evaluations and the validation case indicated this programme as a promising and useful tool for the objective comparison of curves. © 2013 Inderscience Enterprises Ltd. Source

Carrigan C.E.,Roadsafe LLC | Ray M.H.,Roadsafe LLC
WIT Transactions on the Built Environment

Highway crashes result in the death of approximately 41,000 people per year in the United States alone. Roughly one-third of these fatal crashes are with fixed objects along the roadside. An obvious solution for improving roadside safety would be to remove or shield all fixed objects along the roadside. This would certainly decrease the number of fatal and serious injury crashes but could result in the removal of many roadside trees and the installation of hundreds of miles of roadside barrier, leaving an unacceptable aesthetic environment to road users which would also cost many millions of dollars. Removing trees entirely or installing hundreds of miles of roadside barrier, therefore, is not a viable option. A better approach is to understand the highway characteristics that make some locations more prone to crashes and treat the most hazardous locations. It is the objective of this paper to present an example highway design problem which considers design alternatives using a benefit/cost analysis of alternatives to determine the preferred alternative and to minimize all project related costs (i.e., design, construction, right-of-way, etc.) including costs related to crashes. © 2011 WIT Press. Source

Carrigan C.E.,Roadsafe LLC | Ray M.H.,Roadsafe LLC
WIT Transactions on the Built Environment

The current highway design practice in the United States allows for flexibility in application of geometric design principals, however, lacks a formal methodology resulting in varying degrees of application by region, agency and individual. While the consequences of design flexibility (i.e., construction cost, capacity, highway safety, etc.) are recognized, an improved method of quantifying and comparing the consequences of design decisions is needed to allow for more informed decision making. This paper proposes a performance-based design process which can be implemented using the tools, research and published design documentation that exists within the highway engineering community. This process capitalizes on existing workflow for increase acceptance among professionals. Implementation will lead to an improved understanding of the impacts to safety and other outcomes caused by relaxing design standards to accommodate existing ROW, environmental constraints, and other items traditionally viewed as constraints. It is the objective of this paper to present a proposed performance-based highway design process demonstrated using highway safety as the measurable outcome. The proposed process can be extended to include other highway engineering performance outcomes such as vehicle capacity but this paper focuses solely on the safety performance of highway alternatives. © 2011 WIT Press. Source

Ray M.H.,Roadsafe LLC | Carrigan C.E.,Roadsafe LLC | Plaxico C.A.,Roadsafe LLC
Transportation Research Record

This paper presents a new method to rank the severity of an impact with a roadside hazard that is based on observable crash data. This method has been incorporated into the third update of the Roadside Safety Analysis Program. The equivalent fatal crash cost ratio (EFCCR) Is a dimensionless value that represents the severity of a crash on a scale of zero to unity, where zero represents no chance of injury and unity represents absolute certainty of a fatal injury. The method uses a census of police-reported data, which ideally covers a range of speed limits. The purpose Is to determine the severity distribution of crashes in cases in which no events preceded the crashes with the hazard under evaluation and which did not result in a penetration or a rollover. The number of unreported crashes is estimated and added into the severity distribution with the assumption that the number represents crashes that led to property damage only. The average expected crash cost is then calculated and normalized to a reference speed of 65 mph so that it is directly comparable to EFCCR values calculated for other types of hazards. Unlike the earlier subjective severity index method, the new EFCCR method has its basis in observed crash data and uses a systematic approach to calculate crash severities that can be used in benefit-cost and other safety analyses. Source

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