Road networks are the backbone of connectivity across Asia and the Pacific, linking communities to essential services such as hospitals, markets, and schools, and facilitating economic activity across vast distances.

To ensure these vital links remain reliable amid escalating hazards, it is critical to build resilient transport systems. Many existing and newly constructed roads continue to rely on historical data and outdated design standards that no longer reflect current realities.

As a result, infrastructure is increasingly vulnerable to extreme weather events such as washouts from heavy rainfall, landslides, extreme heat, and sea-level rise, thus pushing legacy designs to their limits and threatening the sustainability of prevailing transport networks.

Under projections from 2016 to 2030, transport investment needs across the region may reach around 8ドル.4 trillion (approximately 619ドル billion each year), much of which will go to roads. Making these investments resilient is therefore vital to ensure long-term connectivity and economic growth.

In Timor-Leste, which is a small island developing state that is in a fragile and conflict-affected situation, with rugged, mountainous terrain, the Ermera-Fatubessi road (C13) is a lifeline for upland communities.

Improvements have been made on sections where extreme monsoonal rains repeatedly trigger landslides and washouts that sever access to markets, schools, and healthcare.

Given Timor-Leste’s fragile status, the limited ability of its road agencies presents a significant challenge in adopting effective road management practices.

Many planning tools do not factor in shifting weather and hazard conditions, so decisions about building, repairing, and maintaining roads often overlook risks.

This leads to accelerated deterioration of roads, increased transport costs, reduced service reliability, and compromised long-term sustainability.

Addressing this gap is essential to ensure that road investments are resilient and remain effective under growing environmental and socio-economic pressures.

Timor-Leste’s recent experience underscores how natural hazards can severely disrupt connectivity. Tropical Cyclone Seroja in April 2021 brought torrential rain and landslides that affected over 178,000 people across all 13 districts, washing away roads and bridges and isolating communities.

Even during typical wet seasons, mountainous districts like Ermera face slope failures and road washouts that can block transport for weeks. By 2050, rainfall in Timor-Leste is projected to increase by 10-15%, with extremes up to 20% more intense under high-emission scenarios, raising the risk of chronic disruptions on roads like C13.

The latest scientific assessments warn that extreme weather events are causing more damage to roads and other key infrastructure, underscoring an urgent need for resilience-building measures, not just for individual roads, but for entire transport systems as well.

The United Nations Economic and Social Commission for Asia and the Pacific (UN ESCAP) also projects that the region’s average annual loss from disasters, which includes impacts on the transport sector, could double by 2030 if current trends continue and adaptation measures remain inadequate.

Many planning tools do not factor in shifting weather and hazard conditions.

A key lesson from Timor-Leste’s experience as a fragile island state is the need to move away from a reactive ‘fix it after it breaks’ approach, which has proven costly and unsustainable.

Instead, a proactive strategy is essential, one that integrates multi-hazard risk assessments and natural hazard identification into all stages of road planning, design, and maintenance.

The first critical step in this transition is identifying high-risk road segments that serve vital economic and social functions and are exposed to natural hazards such as flooding, landslides, extreme heat, and sea-level rise.

This shift requires not only technical capacity but also strong, trust-based collaboration between local communities, government agencies, and development partners to support the adoption of resilient design standards and institutional reforms.

For example, in Timor-Leste an assessment pinpointed landslide‐prone sections of C13 using projections and geotechnical data; similarly, analyses identified routes where failure would trigger the most harmful ripple effects.

The second step is to strengthen the resilience of these high-risk roads. On C13 in Timor-Leste, covering about 11 km of high‐risk sections, this means hybrid engineering solutions, such as soil nailing, retaining walls, and gabions paired with nature-based solutions using vetiver grass, gamal trees, and bamboo, plus upsized, lined drainage that can handle intense downpours.

The vegetation also stabilizes soils and provides shade that reduces heat stress on pavements.

The third step is to enhance the ability of agencies to do their work effectively. In Timor-Leste’s experience, the project team pairs the works with asset management and disaster‐risk monitoring, emergency protocols for landslides and floods, and training for government officers and community maintenance groups, including women, to inspect slopes, clear drains, and tend vegetation.

If institutional mandates don’t require engineers to consider future rainfall intensity or extreme weather events, many roads will be doomed to fail.

The fourth step is to embed adaptation measures into road planning, design, and maintenance. Revising future road development to reflect risks and community-level adaptations is essential for long-term infrastructure resilience.

This requires not only alignment with national disaster risk management policies but also a collaborative relationship between the government, local communities and development partners.

Such trust enables technical assistance and institutional support to be effectively delivered, ensuring that risk information is systematically integrated into planning, design, and maintenance processes. Without this framework, even the most advanced technical solutions risk being underutilized.

Across Asia and the Pacific, countries are recognizing that resilient roads bolster everything from individual assets to the overall transport system. Still, challenges remain.

Institutional silos, limited capacity, and lack of budgets may hinder plans and priorities, but targeted adaptation finance can bridge gaps and pilot solutions that scale.

Timor-Leste shows that knowing the full range of risks, and combining smart engineering with stronger local skills, can prevent repeated damage, keep communities linked, and support fair, lasting growth.