Executive Summary : | In 2015 number of deaths in road-related crashes in India has crossed 150, 000 and ever since it has not come down. In fact, the rate of fatalities in these crashes has been continuously increasing. To address this ever-increasing growth rate, MoRTH has reviewed road safety policies with the aims to reduce the fatalities by half by 2020. Of all the crashes various studies estimated that around 20% are due to poor pavement surface characteristics. Road agencies in many countries manage the risk of these crash by maintaining the minimum levels of skid resistance and specify aggregates in surface materials based on associated risk. Such approaches are not yet adopted in India. Therefore, the primary objective of the proposed study will be in contributing in the development of the threshold levels of the skid resistance based on the road geometry to optimize the risk associated with the wet skid crashes. In addition, a detailed guidance on how to achieve these levels for the asphalt and concrete surface materials that are commonly used in India will be developed.
The scope of the project involves developing a model/method to determine the skid resistance offered by the pavement surface course based on the aggregate characteristics and gradation. Aggregates that are commonly used in surface courses of the pavements in India will be characterized using a number of conventional test methods, and aggregate texture will be measured using the imaging analysis. These aggregate properties will be related to skid resistance offered by the commonly adopted asphalt surface types in India. In addition, a database of skid resistance measurements using a Mu-Meter on the asphalt pavement surfaces will be established. Field measurements on selected sections will be conducted using the Mu-Meter. These data and measurements will be used to carry out comprehensive statistical analyses of the influence of aggregate properties and mixture design on the skid-resistance value and its variability. Consequently, a model will be developed for predicting asphalt-pavement skid resistance based on aggregate characteristics and aggregate gradation. The developed model can be used to select the mixture type and aggregate source that is needed to achieve the required level of skid resistance for a given service life. The skid resistance measurements will also be measured at pre-defined time intervals for both concrete and asphalt pavements to develop a skid resistance deterioration model for asphalt mixes adopted in the study and for the common concrete tinning patterns adopted in India.
Road safety in particular highway safety in India can be enhanced if the relationships between the factors which causes wet crashes can be quantified and threshold levels of the skid resistance are developed based on the road geometry to optimize the risk associated with the wet skid crashes. This will also help decision-makers to better allocate resources to address the most serious safety risks. |