[PDF] Safety Effectiveness Evaluation Of Traffic Barrier Systems eBook

Author : United States. National Transportation Safety Board
Publisher :
Page : 48 pages
File Size : 45,74 MB
Release : 1980
Category : Government publications
ISBN :

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Traffic barriers are roadside hardware of various designs and materials which are intended to protect vehicles from such off-the-road hazards as trees, embankments, ravines, signposts, bridge support pillars or abutments, or other hazards. The National Transportation Safety Board (NTSB) has been concerned with the problem of inadequate traffic barriers for several years. The Safety Board has investigated accidents in which barriers failed, and has made recommendations to the FHWA. Of primary importance among these have been recommendations that the FHWA develop and promulgate mandatory performance standards for traffic barriers. The purpose of such standards would be to require that traffic barrier types be crash-tested to demonstrate their ability to meet a set of established safety criteria. At present, barriers are not required to meet such criteria through crash-testing. The purpose of this report is to review past Safety Board concerns regarding the adequacy of bridge and highway rail systems and to evaluate the FHWA's efforts to develop safer traffic barriers. This study analyzes the results of recent crash-testing sponsored by the FHWA and makes recommendations concerning performance standards for traffic barriers.

Author : Malcolm H. Ray
Publisher : Transportation Research Board
Page : 75 pages
File Size : 22,39 MB
Release : 2003
Category : Nature
ISBN : 0309087627

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"This is a report on a research agenda to better inform future societal decisions on ocean CDR [carbon dioxide removal]; the Committee is not advocating either for or against possible future ocean CDR deployments, and the Committee recognizes that ocean CDR would, at best, complement the role of climate mitigation approaches including decarbonization"--Page viii.

Author : Malcolm H. Ray
Publisher :
Page : 172 pages
File Size : 34,64 MB
Release : 1997
Category : Automobiles
ISBN :

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This synthesis will be of interest to state department of transportation (DOT) roadway design, traffic, structural, maintenance, and research engineers and others concerned with highway safety issues. This synthesis describes the current state of the practice for the use of guardrails and median barriers and their crashworthiness. It includes information about the crashworthiness and typical applications of the most common, permanently installed, nonproprietary guardrail and median barrier systems used in the United States today. A significant amount of detail is included in the text to aid the design, selection, and locating processes for safe and effective guardrails and median barriers. The report presents data obtained from a review of the literature and a survey of state DOTs. The synthesis presents a description of the typical longitudinal barriers in use today, including drawings, the extent of their use, and the most recent testing on each guardrail and barrier system, with particular emphasis on NCHRP Report 230 and 350 requirements. In addition, it discusses the maintenance issues, cost constraints, and common problems with each type of barrier. The synthesis only discusses the crashworthiness of guardrails and median barriers; their transitions and terminals are not discussed.

Author : Raghavan Srinivasan
Publisher :
Page : 62 pages
File Size : 30,22 MB
Release : 2017
Category : Head-on collisions
ISBN :

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The Development of Crash Modification Factors program conducted the safety evaluation of cable median barriers in combination with rumble strips on the inside shoulder of divided roads for the Evaluation of Low Cost Safety Improvements Pooled Fund Study. This study evaluated safety effectiveness of cable median barriers in combination with rumble strips on the inside shoulders of divided roads. This strategy is intended to reduce the frequency of cross-median crashes, which tend to be very severe. Geometric, traffic, and crash data were obtained for divided roads in Illinois, Kentucky, and Missouri. To account for potential selection bias and regression-to-the-mean, an empirical Bayes before-after analysis was conducted using reference groups of untreated roads with characteristics similar to those of the treated sites. The analysis also controlled for changes in traffic volumes over time and time trends in crash counts unrelated to the treatment. In Illinois and Kentucky, cable median barriers were introduced many years after the inside shoulder rumble strips were installed; therefore, the evaluation determined the safety effect of implementing cable barriers along sections that already had rumble strips. Conversely, in Missouri, the inside shoulder rumble strips and cable barrier were implemented around the same time. Hence, the evaluation in Missouri determined the combined safety effect of inside shoulder rumble strips and cable barriers. The combined Illinois and Kentucky results indicate about a 27-percent increase in total crashes; a 24-percent decrease in fatal, incapacitating injury crashes; and a 48-percent decrease in head-on plus opposite-direction sideswipe crashes (used as a proxy for cross-median indicator plus head-on). the economic analysis for benefit-cost ratios shows that this strategy is cost beneficial.