Estimation of materials-induced CO2 emission from road construction in Korea

The first attempt has been made in Korea to quantify the carbon dioxide (CO2) emitted from the consumption of main and basic materials for road, bridge and tunnel constructions. These materials-induced CO2 emissions were estimate using the amount of materials consumed and corresponding CO2 emission factors. A simple linear relation was developed between unit price and emission factor for some of basic materials whose emission factors were not available. To demonstrate overall and unit emissions, twelve expressway sections constructed between 2006 and 2007 have been selected and consumed materials have been identified. The unit emissions were then utilized to estimate the total emissions that might have been released from all types of roads (expressways, national highways and local roads) up to the year 2007. Also, the effects of number of traffic lanes and bridge types on the CO2 emissions were briefly discussed. Finally, average annual CO2 emissions were predicted based on road construction plans from 2009 to 2020. One of the results suggested that bridges should induce the largest emissions per meter (120.1 tCO2/m), followed by tunnels (29.6 tCO2/m) and road-only sections (7.5 tCO2/m) due to the consumption of main construction materials.