Roll-on/Roll-off (RO/RO) shipping is unique in providing seamless services of carrying passengers, vehicles, general cargoes on trucks, and containers on chassis without time-consuming lift-on/lift-off operations. RO/RO shipping services are widely used across the world for various routes between islands and/or on by-pass routes avoiding detour transport, taking functional advantage into account. Accordingly, RO/RO shipping services between islands may provide seamless connectivity, especially for the Brunei Darussalam, Indonesia, Malaysia, and Philippines-East Association of Southeast Asian Nations (ASEAN) Growth Area and the Indonesia, Malaysia, and Thailand-Growth Triangle sub-regions. Experience with RO/RO shipping in Northeast Asia and Europe, mostly in Japan and the United Kingdom, is summarized to identify the business conditions conducive to establishing cross-border RO/RO shipping services, particularly physical conditions and traffic demand. RO/RO shipping in ASEAN may play a complementary role in container shipping by providing fast and seamless unitized cargo services on selected feeder routes.