Special Issue Article
A CASE STUDY ON OVERLAY DESIGN USING HDM-4
Highway Development and Management tool, HDM-4 software, developed by the World Bank for global applications is utilized for identifying an optimum maintenance strategy for highway pavements. The study area selected was Seaport-Airport Road (SPAP Road), a two-lane, 11.47km long road at Cochin. Economic analyses of different overlay options were evaluated using HDM-4. The concept of Ultra-Thin Whitetopping has not yet introduced in Kerala. Hence a feasibility check for Ultra-Thin Whitetopping is done. It may be defined as a concrete overlay 50mm to 100mm thick, with closely spaced joints and bonded to an existing bituminous pavement. From the deterioration summary it is identified that even after 15 years, the riding quality of Ultra-Thin Whitetopping is the excellent and the most desirable one without any intervention. Ultra-Thin Whitetopping has the minimum rate of roughness progression which in turn may lead to very low Road User Cost values thus providing 46% increase in the Net Economic Benefits than that of Ordinary Bitumen overlay.