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Browsing by Author "Viner, Helen"

Now showing 1 - 4 of 4
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    Development of a Prediction Model for Splash and Spray
    Flintsch, Gerardo W.; Viner, Helen; Coyle, Fiona; Nesnas, Kamal; Hargreaves, David; Parry, Tony (2012)
    Under some conditions splash and spray create a significant nuisance to road users and some evidence suggests that they contribute to a small but measurable proportion of accidents. This paper reports on the development of a prediction model for splash and spray. The work has been funded by the Federal Highway Administration in order to assist engineers in decisions concerning the type and priority of maintenance on the road network. Ultimately, this could deliver a range of benefits including increased user satisfaction with the network, reduced accidents and a reduction in the detrimental effect of pollutants being deposited on the road verges and street furniture. The approach taken has been, firstly, to develop a method for predicting the depth of water that builds up on the road surface, considering the rainfall rate, pavement geometry and surface type. Models obtained from the literature have been validated through measurements of water depth carried out in a flume, using a number of typical road surfaces. Secondly, computational fluid dynamics has been used to estimate the level of nuisance to road users of the various mechanisms of splash and spray generation.
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    Simulative Polishing In The Laboratory; Comparison With Traffic And Use To Investigate Aggregate Blending
    Dunford, Alan; Viner, Helen; Roe, Peter; Caudwell, Louise (2012)
    Two experiments with the Wehner-Schulze machine, which is designed to apply a controlled amount of polishing to and measure the friction of road surfacing products, are described and their results summarised. In the first experiment the polishing action of the machine is compared to the polishing action of traffic using UK roads. It is shown that there is a strong correlation between friction measured after polishing by traffic in a non-event location and friction measured after polishing in the machine. It is shown that polishing in the machine is more severe than that applied by free-rolling traffic on straight roads. In the second experiment, the machine is used to show that it may be possible to predict the long-term friction performance of asphalt prepared with a blend of coarse aggregates using a mass ratio formula.
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    Splash and Spray Assessment Tool Development Program: Final Report
    Flintsch, Gerardo W.; Tang, Lijie; Katicha, Samer W.; de León Izeppi, Edgar; Viner, Helen; Dunford, Alan; Nesnas, Kamal; Coyle, Fiona; Sanders, Peter; Gibbons, Ronald B.; Williams, Brian M.; Hargreaves, David; Parry, Tony; McGhee, Kevin K.; Larson, Roger M.; Smith, Kelly L. (Virginia Tech. Virginia Tech Transportation Institute, 2014-10-07)
    The effects of vehicle splash and spray are well known to motorists who have driven in wet weather conditions. Research suggests that splash and spray contribute to a small but measurable portion of road traffic accidents and are the source of considerable nuisance to motorists. Splash and spray from highway pavements also can carry a number of pollutants and contaminants. When deposited, these contaminants can be poisonous to plant life and accelerate the corrosion of roadway appurtenances. Splash and spray are individually definable processes that are the product of a number of different factors. Many parties have gone to great lengths to reduce the splash and spray created by motor vehicles, especially that from heavy vehicles, by retrofitting devices that alter the vehicle’s aerodynamics. Another possible solution to the problem is to change the characteristics of the highway pavement. Previous research shows that pavement geometry, drainage, texture, and porosity all contribute to splash and spray generation, but the exact mechanisms are largely unknown. A model capable of predicting the splash and spray propensity of pavements can be used by highway engineers to support decisions in highway maintenance and design. The project objective was to develop a simple and practical assessment tool to characterize the propensity of highway sections to generate splash and spray during rainfall and the impact of splash and spray on road users. This report summarizes the development of the splash and spray model and its implementation in an easy-to-use, practical tool.
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    Use and Limitations of Crash Data in Determining the Priority For Treating Sites with Low Skid Resistance
    Viner, Helen; Coyle, Fiona; Brittain, Stuart; Caudwell, Louise (2012)
    In assessing the treatment of sites with low skid resistance, the relative priority of lengths marginally below skid resistance threshold where there have been a number of recent crashes must be balanced with that of lengths substantially below the threshold with no recent crash history. The judgment is complicated by the highway authority having a duty of care to maintain the road in a safe and serviceable condition, so it is not acceptable to let the skid resistance deteriorate indefinitely, even if there have been no crashes. Furthermore, the analysis lengths are generally short and the number of crashes is generally small, leading to a high degree of uncertainty in estimating the underlying risk. And finally, as there can be a large number of sites that require investigation within any particular jurisdiction, there is a need for a simple method otherwise the whole process of site investigation demands a disproportionate level of staff resource. This paper describes an accident risk model that has been created to provide a simple and consistent method for rating the priority of treatments at locations with low skid resistance and the dilemma for determining how to incorporate crash data within decisions on treatment priority.