详情

原文传递 GUIDELINES FOR REMOVAL OF HANDRAILS ON NARROW CULVERTS AND BRIDGES

题名：	GUIDELINES FOR REMOVAL OF HANDRAILS ON NARROW CULVERTS AND BRIDGES
作者：	Hani G. Melhem Rafael £. Morice Eugene R. Russell Bob L. Smith
关键词：	bridge；rails；arrow；guide；lines；oval；hand；elin；alternative；integrity
摘要：	Old style handrails, parapets, and hub-guards of narrow culverts and bridges on local, low-volume roads (LVR) restrict their use by wide farm equipment and can cause severe damage and personal injury if hit by a vehicle. In many cases, these rigid obstacles can become roadside hazards and may be more of a hazard to the motorist than the streambed or drainage area. The objective of this study is to develop several guidelines for determining when to remove substandard handrails taking into account safety considerations, structural integrity, and cost effectiveness. Eliminating any rigid object in or near the roadway will allow use of the roadway by wide farm equipment and may make for a safer road environment. The ROADSIDE software developed and made available by AASHTO was used in this study to compute accident costs for several combinations of vehicle speeds, culvert widths, and ditch depths for both cases where the handrails are present and when the handrails have been removed. It was found that, based on accident cost, it is recommendable to remove the handrails for culverts having a ditch height of 2.1 meters (7 feet) or less. For all other culvert heights judgment should be used when determining whether or not to remove the handrails. Based on this investigation, site visits, accident data analysis, professional expertise, and engineering judgement, the research team agrees that for bridges or culverts which are 2.4 meters (8 feet) or less in depth, the bridge railing end is probably the greater hazard and for depths greater than about 2.4 meters the bridge rail end may be the lesser hazard. Adding galvanized steel tapered sleeves, extending the culvert to achieve safer end slopes, and attaching end sections with parallel safety bars (grates) are typical procedures recognized by the Federal Highway Administration. Such products and services exist commercially nationwide and are available in Kansas. It is suggested that such alternatives to guard fences and bridge rails on low-volume roads be investigated in further depth.
报告类型：	科技报告