The ATO green roads profiles present country-level perspectives on how 35 Asia-Pacific economies are addressing the development and management of sustainable eco-friendly roads. Drawing from diverse datasets and policy documents, the profiles highlight practices and measures that contribute to greener transport infrastructure.

Developed by the Asian Transport Observatory (ATO) in partnership with the International Road Federation (IRF), the profiles are designed to complement the Green Roads Toolkit. The toolkit provides a practical reference for integrating good practices across nine dimensions:

• Decarbonization
• Climate resilience
• Water and land management
• Pollution reduction
• Conserving biodiversity
• Responsible sourcing of materials
• Improving quality of life
• Disaster preparedness
• Fostering inclusive growth

This 2025 edition builds on earlier work to provide a comprehensive resource for guiding the planning, development, construction, and management of greener, more sustainable roads.

Thailand's road network spanning over 703,000 kilometers, serves as the undeniable backbone of the nation's connectivity. Composed largely of local and rural routes, which make up 92% of the total system, this infrastructure supports a density of 1,378 meters per square kilometer—a figure that speaks to decades of expansion. Yet, this physical asset is becoming a focal point for three converging crises: escalating greenhouse gas emissions, ecological fragmentation, and vulnerability to a volatile climate.

The carbon footprint of Thailand transport is overwhelmingly road-based. By 2024, road transport generated 81.1 million tonnes of CO2e, accounting for 96% of the sector's total emissions and 19% of the economy-wide total. While economy-wide emissions grew at 1.9% annually since 2000, road transport outpaced them, climbing at 2.5% per year. This trajectory is driven by high motorization rates—600 vehicles per thousand people, nearly double the Asia-Pacific average—and a fleet composition dominated by personal mobility. Two-wheelers (57%) and light-duty vehicles (40%), while buses represent a negligible fraction of the traffic mix, reflecting a systemic underinvestment in mass transit.

A pivot is visible, however. Thailand has emerged as a regional leader in electrification, scoring 82 out of 100 on UNEP's E-mobility Readiness Index. The market has responded swiftly; between 2015 and 2024, the value of EV imports reached 6.6 billion USD, capturing 50% of road vehicle imports by the end of that period. Yet, the decarbonization potential of these vehicles is tethered to the power sector. With a grid emission factor of 555 gCO2 per kWh, the new fleets are only marginally cleaner than the regional average, dampening the immediate climate benefits.

Beyond the tailpipe, the road network itself represents a massive accumulation of embodied carbon. The infrastructure stock contains approximately 3.07 billion tonnes of material, with annual maintenance and expansion adding another 79 million tonnes—equivalent to 2.7 million tonnes of embodied CO2e every year. This physical footprint weighs heavily on Thailand's biodiversity. Of the country's 114 Key Biodiversity Areas (KBAs), 102 have been bisected by road infrastructure, creating a density of 387 meters of road per thousand square kilometers within these sensitive zones—far exceeding the Southeast Asian average of 83. Current mapping of 61 pending road projects suggests further risks, potentially endangering over 5 million tonnes of carbon stocks and compromising nitrogen retention critical for vegetation.

Climate resilience is the other side of the infrastructure coin. Under a 4.5-degree warming scenario, nearly 88% of Thailand's road and rail assets face exposure to intensified precipitation. The economic implications are already tangible. Average annual losses to transport infrastructure are estimated at 125.8 million USD, with roads absorbing 78% of this damage. Bridges and tunnels serve as critical failure points; despite accounting for only 0.3% of the infrastructure, they suffer 5.4% of the losses. This vulnerability extends to the rural population, where 2.2 million people remain beyond the reach of all-season roads, leaving them isolated during disaster events and severing access to markets and healthcare.

Safety remains the most immediate human crisis. The current mobility model extracts a severe toll, with the World Health Organization estimating 18,218 road crash fatalities in 2021. The impact of road crashes extends far beyond human suffering. These fatalities and serious injuries cost Thailand approximately 36 billion USD in 2021, roughly 7% of the country's GDP. For comparison, healthcare expenditure in Thailand in the same year amounted to only 5.2% of its GDP. In Thailand, road crash fatalities decreased by approximately -5.9% per year between 2016 and 2021. However, this is not enough to reach the 2030 target to halve the fatalities by 2030

Simultaneously, urban accessibility is skewed. In 63% of cities with data available, only two out of ten residents have access to public transport, and merely 33% of the urban population can access essential healthcare and education within a reasonable one-kilometer distance.

The transition to "green roads" in Thailand demands a systemic shift toward network efficiency—currently scoring just 0.63 out of 1.0—and a rigorous integration of biodiversity safeguards into infrastructure planning. Future policy must bridge the gap between rapid fleet electrification and the hardening of physical assets against climate shocks.

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