DESIGN ANALYSIS FOR THE UNDERGROUND RELOCATION OF A CENTRAL ROAD ARTERY IN ATHENS

The development of underground transportation infrastructure, can provide efficient solutions to alleviate congestion problems in the existing surface road network, enhance mobility conditions and can provide the setting for reclaiming valuable urban space so as to regenerate and revive city life. The paper deals with the design of the underground relocation of a major road artery (Piraeus avenue), which is located in the heart of Athens, Greece, suffering from severe congestion problems as it interconnects with another central avenue. The design route alternatives and their main characteristics are presented and evaluated, while the selected design is analyzed. The proposed final solution has a total length of approximately 617m, with the underground section being around 407m. The design process is presented and the construction sequence is illustrated in the paper, following the top-down method (cover-and-cut), in order to maintain the traffic access and avoid inconveniences to neighboring communities during the development phase of the project. The cost of the project is estimated and finally, in order to demonstrate the potential benefits gained from the underground project, the findings from a nonmarket analysis are presented, based on the benefit-transfer methodology.