Besides the direct impact on trade and economic growth, transport networks would have several positive externalities, or unintended benefits. Enhanced intraregional connectivity will open up possibilities for production networks and value chains to develop within the subregion, enhancing the competitiveness of final products from the region on world markets. South and South-West Asia’s transport corridors possess the potential to achieve massive efficiency gains and energy savings, thus opening up new pathways towards sustainable development. While transport infrastructure and services have been improving in all South Asian countries at varying paces, cross-border transport facilitation still has much room for progress.