'Road use phase' environmental indicator for sustainable pavement management system

Once a road is constructed, it enters into use or operation phase as part of a road network. The road use phase involves management of road maintenance and rehabilitation activities to keep the road functional based on certain approved intervention triggers, maintenance work standards and budget. Road agencies usually have a Pavement Management System (PMS) in place that prioritizes road sections for maintenance and rehabilitation works. This is primarily based on economic indicators. With the emergence of sustainable development concept to address the climate change phenomena as a principal concern for human sustenance on the earth, consideration to environmental issue like carbon emissions is becoming an internationally agreed requirement. This needs a holistic indicator that can address key road environmental components during the use phase for comparing different maintenance strategies based on Global Warming Potential (GWP). This paper presents an environmental indicator concept termed as ‘Road Use GHG Factor (RUGF)’, which could be used to calculate life cycle carbon footprint of alternative road maintenance strategies. RUGF provides combined GWP of key use phase environmental components like rolling resistance, albedo and construction materials. The application of RUGF leads to the development of a comprehensive sustainability parameter ‘Road Sustainability Factor (RSF)’ that can accommodate different indicators of sustainability in road project development and management. Incorporation of RSF may help upgrade the PMSs to Sustainable Pavement Management Systems (SPMS).