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.

Cambodia's mobility landscape is characterized by significant inequality. The country has 78.4 thousand kilometers of roads, mostly consisting of local and rural types—92%—with only 2% being motorways and main highways. Infrastructure density is low at 444 meters per square kilometer. Despite gradual improvements—an increase from 3.5 km per thousand people in 2000 to 4.4 in 2024—the physical infrastructure is still inadequate for the country's economic goals.

Motorization rates tell a misleading story. With just 55 vehicles per thousand people in 2024, Cambodia seems to be in early stages of mobility compared to the Asia-Pacific average of 317. However, its environmental impact is substantial, with road transport greenhouse gases reaching 5.9 million tonnes of CO2e in 2024. Emissions are not only rising but doing so at 7.1% annually, nearly double the economic growth rate of 3.8%. The road transport sector accounts for 81% of total transport emissions. The primary driver of pollution isn't private cars but heavy vehicles. Heavy-duty vehicles (HDVs) produce 64% of transport-related CO2 emissions, even though the fleet mainly consists of two-wheelers (41%) and light-duty vehicles (47%). This indicates structural inefficiency. Carbon intensity per GDP has increased from 15 grams of CO2e per USD in 1990 to 42 grams in 2024, higher than the regional average of 26 grams. Since 2015, progress has been slow, with a slight annual decrease of 2.0%, compared to a sharper regional reduction of 5.4%.

Electrification presents a brighter outlook. Between 2015 and 2024, EV imports reached 172 million USD, representing 9% of total vehicle imports by 2024 (by value). However, the energy powering these vehicles remains not entirely green; the grid's emission factor is 498 gCO2 per kWh, slightly cleaner than the regional average of 559. Yet, Cambodia's grid intensity has increased slightly since 2015, contrasting with regional improvements.

Air quality issues are significant. PM 2.5 levels averaged 21.3 micrograms per cubic meter, causing at least 215 early deaths. The economic toll is substantial; the World Bank estimates health damages from PM 2.5 exposure at around 6.3 billion USD annually—about 8% of GDP—with road transport responsible for 15% of this pollution. Climate vulnerability worsens the risk. Under a 4.5°C warming scenario, over half (52%) of Cambodia's road and rail assets could face damage from extreme rainfall. Infrastructure losses average 4.5 million USD annually, mainly affecting roads (91%) and, to a lesser extent, bridges and tunnels (2.2%), despite their small physical share.

The road network impacts nature and social equity. Cambodia's forests, covering 43% of land, are increasingly encroached upon—35 of 45 Key Biodiversity Areas are now intersected by roads. This results in 45 meters of road per thousand square kilometers of protected land, lower than Southeast Asia's average but still causing fragmentation.

On the social side, millions remain disconnected. About 2.9 million rural residents live more than two kilometers from all-season roads. Urban accessibility is also unequal, with only 20% having easy access to public transport. In Cambodia, 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; 3,113 lives were lost in 2021.

The transport workforce employs about 434,000 people, yet women only make up 7.4%, highlighting gender disparities. Overall, Cambodia faces a complex challenge. The country exhibits low vehicle ownership but high emissions from a legacy fleet, a fragile network vulnerable to climate shocks, and social benefits that lag behind infrastructure investments. Without urgent action—particularly in decarbonizing freight, strengthening infrastructure, and improving rural access—the road sector risks becoming a burden rather than a driver of development.

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