Comprehensive model for upgrading two-lane road network

Abstract

Concept: Trough rational approach adapted to the actual condition and needs of national and regional network; a Road Upgrading Management model has been elaborated providing the optimum upgrading strategy in each case. Starting from the simplest to the heaviest and most costly, the model envisages, for each road held for upgrading, the options of 'Maintenance', 'Rehabilitation', 'Reconstruction' and 'New Alignment'. Methods: The choice among these strategies is based on a mathematical algorithm consisting of an effective sequential structure. Facing each concrete case of an aged road, the first step is to proceed to a site survey providing road geometric features, pavement characteristics and traffic volume. The level of service (LOS) derived is compared to the level of service required. While proceeding to the threshold examination of geometric features in a realistic way, the proposed model provides respective appropriate values related to actual needs. Results: After an exhaustive consideration of geometric features and indices of environmental, socio-economic adaptation, the upgrading strategies are examined and eventually overruled one by one, finally leading to the optimum alternative. Conclusions: This paper deals with the main issue of quantitative and qualitative criteria definition, in order to proceed to such a full road condition assessment. Road authorities can use this approach as a reliable tool in the frames of an effective road upgrading management. © 2012 The Author(s).