border when the Federation of Malaya, Singapore, Sabah and Sarawak merged to form Malaysia on 16 September 1963. On 22 July 1964, as part of a curfew after racial riots in Singapore, the Causeway was closed to travellers without police permission. It was reopened during non-curfew hours the following day and normal traffic had resumed by 26 July. After Singapore's separation from Malaysia on 9 August 1965, the Causeway became the border connector between the two countries. Immigration checkpoints were built on both sides, with passport controls implemented on the Singaporean side from June 1967 and on the Malaysian side from September. To support the ever-increasing trade and foot traffic on the Causeway, both the Malaysian and Singapore governments carried out works to widen the Causeway multiple times as well as to improve checkpoint facilities. Singapore replaced its checkpoint in 1999, followed by Malaysia in 2008. A second border crossing bridge, the Malaysia–Singapore Second Link between Tanjung Kupang and Tuas, was completed in 1998. In response to the COVID-19 pandemic, Malaysia instituted a nationwide movement control order on 18 March 2020 and closed the country's borders, affecting hundreds of thousands of cross-border commuters between Malaysia and Singapore. However, the flow of cargo, goods and food supplies continued. On 29 November 2021, authorities of both countries eased their land border controls, and began to allow a restricted daily flow of 2,880 residents to travel between the countries by the Causeway under a vaccinated travel lane scheme via designated bus services. However as the infections of the SARS-CoV-2 Omicron variant spiked, the number of travellers allowed was halved between 23 December 2021 and 20 January 2022. The quota of daily passengers was increased to 3,420 on 14 March 2022. From 1 April 2022, the quota was lifted with no restrictions imposed on the mode of travel across the land connections. Border checkpoints Southern Integrated Gateway The Southern Integrated Gateway consists of the Sultan Iskandar Building and the Johor Bahru Sentral railway station (JB Sentral). Sultan Iskandar Building is the customs, immigration and quarantine (CIQ) complex handling road traffic and pedestrians. It was officially opened by the Malaysian Prime Minister, Abdullah Badawi on 1 December 2008 and went into full operations on 16 December 2008. The old Tanjung Puteri CIQ complex was subsequently demolished. As the new CIQ complex was located 1 km further inland from the old checkpoint, as well as the