Modeling traffic barriers crash severity by considering the effect of traffic barrier dimensions

Abstract

Traffic barriers are in widespread all around the USA as safety countermeasures for reducing the severity of runoff road crashes. The effect of traffic barriers' dimension had been ignored in past real-world crash studies due to the considerable cost and time needed for collecting field data. This paper presented two new analytical models to investigate the effect of different variables on the severity of crashes involving traffic barriers, and end treatments. For this reason, a field survey was conducted on over 1.3 million linear feet of traffic barriers (approximately 4,176 miles road) in Wyoming to measure traffic barriers' geometric features like height, length, offset, and slope rate. The collected data included 55% of all non-interstate roads of Wyoming. Based on results, the crashes involving box beam barriers were less severe than the crashes involved with W-beam or concrete barriers. The traffic barriers with a height between 28 and 31 in. were found safer than the traffic barriers shorter than 28 in., while there was no significant difference between the traffic barriers taller than 31 in. to those shorter than 28 in. in terms of crash severity. The end treatments located nearer to the traffic lane had lower crash severity. Keywords Crash severity Á Runoff road crashes Á Traffic barriers Á End treatments Á Traffic barrier dimensions Á Real-world crash analysis Á Wyoming

Optimization of Dynamic Mechanical Properties of Knitted Barrier Meshes

“…Another important parameter is the cover factor that by an even distribution of threads in the mesh arms determines the distribution of stresses and deformations in the surface and volume of the mesh. Table 1 show that -the heaviest model is the four-axial eight-thread mesh with square a-jour structure with a weight of 12.50 kg and a volume of 8.62 dm 3 . The next one is the mesh with diamond-shaped a-jour geometry with a mass of 10.47 kg and a volume of 7.22 dm 3 .…”

“…Table 1 show that -the heaviest model is the four-axial eight-thread mesh with square a-jour structure with a weight of 12.50 kg and a volume of 8.62 dm 3 . The next one is the mesh with diamond-shaped a-jour geometry with a mass of 10.47 kg and a volume of 7.22 dm 3 . The third heaviest model is the mesh with regular hexagonal a-jour structure of "inverted honeycomb" with two axes, whose mass is 10.21 kg and volume equals 7.04 dm 3 .…”

“…The next one is the mesh with diamond-shaped a-jour geometry with a mass of 10.47 kg and a volume of 7.22 dm 3 . The third heaviest model is the mesh with regular hexagonal a-jour structure of "inverted honeycomb" with two axes, whose mass is 10.21 kg and volume equals 7.04 dm 3 . The next one is the mesh with regular hexagonal a-jour geometry in the shape of a "honeycomb" with two axes, whose mass is 9.58 kg and volume is 6.60 dm 3 .…”

“…The third heaviest model is the mesh with regular hexagonal a-jour structure of "inverted honeycomb" with two axes, whose mass is 10.21 kg and volume equals 7.04 dm 3 . The next one is the mesh with regular hexagonal a-jour geometry in the shape of a "honeycomb" with two axes, whose mass is 9.58 kg and volume is 6.60 dm 3 . Similar meshes with large mass and not less than 9 kg are -the mesh with irregular hexagonal a-jour structure with two axes Ms = 9.37 kg, the one with irregular hexagonal a-jour geometry with oblique axes 2 Ms = 10.06 kg, and the mesh whose a-jour structure is a four-axial six-thread square 3 Ms = 9.32 kg.…”

“…This article focuses on the analysis of mechanical properties of knitted barrier meshes. It also refers to more general problems related to safety engineering, including road safety, in particular securing dangerous sections on road curves, especially on mountain roads, in places at risk of rock landslide, on viaducts, and in railroad crossings [1][2][3][4]. Barrier meshes can be applied in all those cases, and additionally they can also serve as barriers against avalanches or snow, and as a protection for mountain trails or ski runs.…”