Condition Data in Road Maintenance Management

MSc (CE) Antti Ruotoistenmäki is presenting his doctoral dissertation “Condition Data in Road Maintenance Management” for public examination on Friday, 16 November at 2 pm at the HSE Economicum lecture hall (Arkadiankatu 7). The dissertation belongs to the Quantitative Methods of Economics and Management Science. His opponent is Professor Andrus Aavik of Tallinn University of Technology and the custos (chairman) is Professor Tomi Seppälä of HSE.

The total asset value of Finnish infrastructure is € 120 billion, of which the value of public road network administered by the Finnish Road Administration is some € 15 billion. Its annual maintenance and rehabilitation budget is approximately € 200 million. The condition of the road network, a key input to the management process, affects the annual road user costs of some € 10 billion. It is also used for evaluating maintenance benefits.

In his dissertation, Ruotoistenmäki is focusing to the information collected from paved road network of its surface profile (serviceability), cracking (automated image capturing and processing) and deflections measured using the falling weight deflectometer. The latter describe the road structural condition. Ruotoistenmäki uses several statistical methods, partly so as to choose the most appropriate method for accomplishing each task, and partly so as to create different views on the subject, which regardless of its economical importance has been the subject of surprisingly little statistical research.

The owners of road and street networks, as well as those collecting and analysing condition data, may apply the results of this study in their operations. Especially in the long-term maintenance contract the responsibility of meeting the functional requirements (condition) belongs to the contractor who may benefit from the results of this study. Focusing on maintenance of paved roads, the results of this study can be generalised to infrastructure asset management.

Ruotoistenmäki shows that the normality of the distribution of condition indicators, desirable in their statistical analysis, can often be achieved using logarithmic transformation. This enables the comparison of relative accuracies from various measurements with different scales. Using the route optimisation method developed in this study, the measurement budget can be allocated cost-effectively so that only those sections are measured where the benefits of improved accuracy in maintenance decision-making are the greatest. The current measurement policy is to measure high-trafficked roads every year, but in one direction only. The measurement budget could be reallocated so that all lanes are measured every other year.

Antti Ruotoistenmäki works as a leading consultant in the Consulting services unit of Destia in Helsinki since February 2007. He received his MSc (CE) from Helsinki University of Technology in 1994, and has previously worked as a researcher at the Technical Research Centre of Finland and Helsinki School of Economics, and as a consultant in Inframan Ltd. and Pöyry Infra Oy. His professional tasks are related with road maintenance management and condition measurements.