The benefits of sustainable road management: a case study

This paper concerns the economic sustainability of appropriately maintained road networks and by means of a case study demonstrates how it can be achieved by utilising fully the resources available for road management. First, it discusses the concept of sustainability in relation to road management. Then it presents how a highway management system was introduced and subsequently been operated for 25 years in a sustainable manner by examining aspects associated with its main technical components, namely: data collection, standards, treatment selection, and prioritisation. It identifies the factors associated with the successful adoption and use of the system by the road authority concerned. To demonstrate the sustainability of the system, valuations of the road asset and measures of its condition are given. The results confirm the preservation of the asset value, as effected by the implementation of appropriate maintenance management, showing that a road authority can achieve its operational objectives if it is committed to a systematic implementation of robust engineering and management principles. </jats:p

Using support vector machines to predict the probability of pavement failure

This paper presents a method to predict the probability of structural failure of road pavements using information contained in road data sets. Expert knowledge was used to develop failure charts to identify the potential factors that may contribute towards pavement failure. A computational technique (a support vector machine) was built to use this information to determine, from the data sets, the probability of failure of individual road sections. With this prediction comes an indication of the predominant failure types, the causes of structural failure and the risk profile of a road network. The usefulness of the approach was demonstrated on a data set taken from the New Zealand long-term pavement performance study of state highways. Analysis of the data set showed that the network was in good condition, but a small number of pavement sections with a high likelihood of failure were identified. Furthermore, the application of the failure paths examined the three predominant failure types occurring on the network and identified their possible causes. Rutting appears to be significantly influenced by the road pavement strength, fatigue cracking seems to be affected notably by the environment (i.e. water ingress) and shear failure is caused primarily by the combination of traffic, pavement composition and strength. In addition, it was confirmed that measured functional pavement condition alone is not a good identifier of failure and that the inclusion of a parameter related to strength, such as pavement deflection, is essential. </jats:p

The evidence for rural road technology in low income countries

Rural road networks in low-income countries (LICs) and low/middle-income countries (LMICs) are critical for economic and social well-being. However, they are mostly unpaved, are of poor average condition, can be impassable after periods of rain and have high user costs. There is therefore a need to identify low-cost, proven sustainable solutions for rural roads in these countries. To this end, the UK Department for International Development commissioned a systematic review to identify and appraise technologies appropriate for low-volume rural roads that have enabled improved and sustainable rural access in LICs and LMICs. Its findings are summarised in this paper. The review found that there is an evidence base of engineering-related technologies (primarily associated with the use of materials and design philosophies) that could be used to improve the performance of gravel or earth rural roads and that proper construction and appropriate maintenance are vital for the technologies to be sustainable in physical terms. However, the review argues that, since there are few empirical studies demonstrating the sustainability of rural road technologies, expert knowledge is needed to support the implementation of its findings. </jats:p