Roadsafe LLC

Canton, ME, United States

Roadsafe LLC

Canton, ME, United States
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Carrigan C.E.,RoadSafe LLC | Johnson T.O.,RoadSafe LLC | Ray M.H.,RoadSafe LLC
Transportation Research Record | Year: 2016

Improvement projects are increasingly introducing landscape elements to add aesthetic appeal to the projects. Though effective for improving aesthetics, the introduction of trees on the roadside may increase the risk of fatal or incapacitating crashes. In general, the goal of roadside design is to minimize, in so far as is practical, the chance of fatal or incapacitating injury crashes on the roadside. It may not be possible to minimize that risk to the level implied in AASHTO's Roadside Design Guide while capturing the benefits provided by trees, but it is still desirable to understand the risk presented by the presence of trees and balance that risk with the aesthetic benefits. The widely adopted benefit-cost methods currently used in the Roadside Design Guide present a significant challenge with respect to the consideration of trees. Many purported benefits of trees have not been or cannot be quantified in dollars; this lack makes the traditional unit of measurement (i.e., dollars) in a benefit-cost analysis unavailable. This paper presents a quantitative approach for assessing the risk of fatal and incapacitating injuries presented by various tree spacing and offsets. This approach can be applied to any roadway where tree planting or removal is being considered, to quantify the risk of the current and proposed tree locations such that informed decisions can be made about the risk introduced by trees and whether the risks outweigh the benefits. © 2016, National Research Council. All rights reserved.


Mongiardini M.,University of Nebraska - Lincoln | Ray M.H.,Roadsafe LLC | Plaxico C.A.,Roadsafe LLC
International Journal of Computer Applications in Technology | Year: 2013

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.


Heath D.,AECOM Technology Corporation | Silvestri C.,Texas A&M University | Ray M.,Roadsafe LLC
Transportation Research Record | Year: 2012

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.


Carrigan C.E.,RoadSafe LLC | Ray M.H.,RoadSafe LLC
WIT Transactions on the Built Environment | Year: 2011

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.


Carrigan C.E.,RoadSafe LLC | Ray M.H.,RoadSafe LLC
WIT Transactions on the Built Environment | Year: 2011

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.


Carrigan C.E.,RoadSafe LLC | Ray M.H.,RoadSafe LLC | Johnson T.O.,RoadSafe LLC
Transportation Research Record | Year: 2014

Encroachment data gathering in the past explicitly excluded heavy vehicles; this exclusion compelled assumptions to be made about the frequency at which heavy vehicles encroached onto the roadside. This paper examines the assumption that heavy vehicles encroach onto the roadside at the same rate as passenger vehicles. This assumption may be untrue for several reasons. In general, heavy vehicles are driven by trained professionals, who operate with additional restrictions on operating hours. Driver behavior and the performance characteristics of heavy vehicles differ from those of passenger vehicles. In this study, four data sets were analyzed: a national sample, two statewide samples, and a regional sample. The results challenged the long-held assumption that heavy vehicles encroached at the same frequency as passenger vehicles. The findings indicated that heavy vehicles encroached at approximately 30% of the rate of all vehicles. Although the causes of this reduced encroachment rate remain speculative, the examined data demonstrate that a difference does exist and should be accounted for in the modeling of run-off-road crashes for roadside safety benefit-cost and risk analyses.


Ray M.H.,RoadSafe LLC | Carrigan C.E.,RoadSafe LLC | Plaxico C.A.,RoadSafe LLC
Transportation Research Record | Year: 2014

Although six test levels have been available for 20 years to develop a longitudinal barrier, guidelines on how to choose bridge railings on the basis of specific site and traffic conditions have not been developed that take advantage of the range of crash-tested bridge railing hardware. The research reported in this paper was performed to develop such guidelines. During the guidelines' development, several important issues emerged that quantified how the site, traffic, and cost characteristics of a project site should be characterized. This paper presents the issues and discusses the applied solutions. A sample set of bridge rail selection tables is presented with use of the solutions discussed, and the sample is compared with bridge railing selection tables documented in the literature. Although the specific example discussed in this paper involves the selection of bridge railings on the basis of site and traffic conditions, the same procedure can be used to develop most other roadside safety selection and location tables.


Ray M.H.,RoadSafe LLC | Carrigan C.E.,RoadSafe LLC | Plaxico C.A.,RoadSafe LLC
Transportation Research Record | Year: 2014

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.

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