ENCROACHMENTS ON HIGH-SPEED ROADS

This paper describes a study that was undertaken for VicRoads in order to quantify the frequency, nature and spatial distribution of injury-related crashes involving median encroachments on Victoria's divided roads. Over the past decade, over 3,600 reported casualty crashes have occurred because of vehicles encroaching into medians on all classes of road. These crashes have claimed more than 200 lives and led to nearly 2,000 serious injuries. The magnitude and severity of this source of road trauma indicates that a review of this crash problem is necessary. The study involved an analysis of Victoria's road injury problem resulting from all vehicles, including motorcycles, leaving the roadway, either as a primary or subsequent event, and encroaching into the median. An overview is presented of the crash problem, including the spatial distribution of crashes. Median safety along specific high-speed routes was assessed, including the safety and cost impacts. The analysis commenced with all median encroachment crashes, before looking separately at the sub-set of crashes occurring on high-speed roads (100 and 110 km/h). It was found that median encroachments on all roads typically lead to three main crash types, namely, head-on collisions (18% of median encroachment casualty crashes), collisions with fixed hazards within the medians, such as trees, poles or other structures, or a range of other injury-producing events, such as vehicle roll-over or rider falls. Valuable opportunities were identified to invest in the road infrastructure to address problems of death and injury caused by median encroachments. Indicative Benefit-to-Cost Ratios for the installation of median barriers are, in some typical cases, as high as 8:1. This is around twice the estimate for recent Victorian black spot programs and would be considerably higher if less conservative estimates of barrier project life and/or barrier maintenance costs were to be used in the evaluation of economic impacts. The paper concludes with recommendations for addressing median encroachment problems on existing high-speed roads. It also highlights the importance of installing median barriers on all new, high-speed divided roads to avoid serious trauma involving median encroachments in the future. Strengthening Victoria's road infrastructure design practices in this way can be expected to cost-effectively address a source of serious trauma on Victoria's roads. The principles involved are applicable nationally and, potentially, in most motorized countries of the world.

Language

  • English

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  • Accession Number: 00964399
  • Record Type: Publication
  • ISBN: 087659229X
  • Files: TRIS
  • Created Date: Oct 21 2003 12:00AM