This paper exploits Uganda’s large-scale road-upgrading programme—spanning 2006–2023 and covering 2,100 km of primary corridors—to estimate the causal impact of domestic road infrastructure on international trade. Combining geolocated project data with firm-level customs records, satellite-based travel-time indices, and a difference-in-differences design, we find that a 10% reduction in domestic travel time to a border or port raises manufacturing exports by 7.3% and processed agricultural exports by 4.6%.

Heterogeneous effects:

The effects are strongest for small and medium-sized firms and for products with time-sensitive or high-weight-to-value ratios.

Extensive margin:

Improved roads also increase the extensive margin of trade: the number of exporting firms rises by 9% in treated districts, driven by new entrants in textiles and horticulture.

Import effects:

Import flows exhibit parallel gains, concentrated in intermediate and capital goods.

Counterfactual simulations:

Counterfactual simulations indicate that the completed road programme has lifted Uganda’s total trade value by US$1.2 billion (2.8% of GDP) and reduced unit transport costs by 12%. These gains are equivalent to a 4-percentage-point tariff cut for the median sector.

Conclusion:

Our results highlight that, for a landlocked country, high-quality domestic roads are a first-order determinant of export competitiveness and regional integration.