Malaysia has committed to reduce its greenhouse gas (GHG) emissions by up to 45 % by the 2030. With increasing urbanisation and living standards of people in Malaysia, there is certainty that there will be a substantial increase in human activities hence mobility via networks of the highway. Rest and Service Area (RSA) is one important facility of the highway network that operates 24 hours and utilises significant amount of energy for its lighting, cooling, and the restaurants activities. A substantial amount of carbon is emitted from the RSA due to electricity usage, water consumption, solid waste and wastewater, as well as fuel consumption from staff commuting and transportation of goods. The objective of this study is to identify the sources and estimate the operational carbon footprint at RSA Highway Malaysia. The collected data questionnaire was analysed using Microsoft Excel. As expected, the amount of CO2 emissions from electric consumption for each selected RSA about 90 to 94 % of carbon release compare to other sources. As a conclusion, the investments including a more efficient HVAC system and more efficient lighting, could make the building more energy efficient and may induce greater use.