comprehensive rail transport system by expanding the rail system to a total of by the year 2030, with eight in ten households living within a 10-minute walking distance of an MRT station. The current MRT network consists of six main lines: the North South Line, East West Line, Circle Line and partially-opened Thomson–East Coast Line operated by SMRT Trains (SMRT Corporation) and the North East Line and Downtown Line operated by SBS Transit. Two more lines, the Jurong Region Line and the Cross Island Line, will open in stages from 2027 and 2030 respectively. Light Rail Transit (LRT) In several new towns, automated rubber-tyred light rail transit systems function as feeders to the main MRT network in lieu of feeder buses. The first LRT line, which is operated by SMRT Light Rail, opened in Bukit Panjang in 1999 to provide a connection to Choa Chu Kang in neighbouring Choa Chu Kang New Town. Although subsequently hit by over 50 incidents, some of which resulted in several days of system suspension, similar systems albeit from a different company were introduced in Sengkang and Punggol in 2003 and 2005 respectively, both operated by SBS Transit. International rail links The international railway line to Malaysia is an extension of the Malaysian rail network operated by Keretapi Tanah Melayu (Malayan Railways). Since 1 July 2011, Woodlands Train Checkpoint serves as the southern terminus of the KTM rail network. Previously, KTM trains terminated at Tanjong Pagar railway station in central Singapore. One more rail link is being planned: the Johor Bahru-Singapore Rapid Transit System between Woodlands North and Bukit Chagar, Johor Bahru. Air transport Airlines The national flag carrier is Singapore Airlines. In total, there are three local airlines, all operating out of Changi Airport: Jetstar Asia Airways Scoot Singapore Airlines Malaysia's Firefly is the sole operator with scheduled services out of Seletar Airport. Airports The aviation industry is regulated by the Civil Aviation Authority of Singapore, a statutory board of the Singapore government under the Ministry of Transport. An open skies agreement was concluded with the United Kingdom in October 2007 permitting unrestricted services from Singapore by UK carriers. Singapore carriers were allowed to operate domestic UK services as well as services beyond London Heathrow to a number of destinations, including the United States along with Canada. Singapore Changi Airport, with its four terminals, is one of the most important air hubs in the