The Sustainable Land Transport Indicators on Energy Efficiency and GHG Emissions in ASEAN – Guidelines (hereinafter ‘Guidelines’) aims to support the harmonisation across  ASEAN of the monitoring of land transport indicators, with a certain focus on energy  efficiency and greenhouse gas emissions. This document was developed in accordance with the Sustainable Transport (ST) milestone ST-2.3 of the ASEAN Kuala Lumpur Transport  Strategic Plan: ‘the development of a monitoring framework and harmonised approach  for indicators on energy and greenhouse gas (GHG) emissions in the transport sector.’ It  presents indicators as variables meant to accurately represent the sustainability aspects of  land transport. Such indicators are critical in informing policy and investment decisions by  enabling performance tracking throughout time, and by enabling a better understanding of  the underlying factors that impact such performance. These Guidelines provide technical  information and practical insights related to the generation of data for the calculation,  reporting, and interpretation of such indicators.