The Johor–Singapore Causeway is a 1.056-kilometre (0.66 mi) causeway across the Straits of Johor. The Causeway links Johor Bahru in Malaysia to Woodlands in Singapore. It is one of the busiest border crossings in the world, with 350,000 road and rail travellers daily. The under construction Johor Bahru–Singapore Rapid Transit System is expected to relieve The Causeway's traveller numbers by 35% upon opening, currently scheduled for December 2026. The Causeway also serves as a water pipeline between the two countries.
The Causeway officially opened in 1923. Its construction interrupted the water flow through the Straits of Johor, especially after the post World War II permanent closure of the lock channel. Retreating Allied forces blew up The Causeway in two places in World War II. That forced the advancing Imperial Japanese Army to instead cross the Straits elsewhere.