The expressways of Singapore are special roads that allow motorists to travel quickly from one urban area to another. Construction of the system was authorized when construction of the Pan Island Expressway began in 1962. All of them are dual carriageways with grade-separated access. They usually have three to four lanes in each direction, although there are two-lane carriageways at many expressway intersections and five-lane carriageways in some places. There are ten expressways. Studies about the feasibility of additional expressways are ongoing. Construction on the first expressway, the Pan Island Expressway, started in 1966. , there are of expressways in Singapore. The Singaporean expressway networks are connected with Malaysian expressway networks via Ayer Rajah Expressway (connects with the Second Link Expressway in Malaysia) and Bukit Timah Expressway (connects with the Johor Bahru Eastern Dispersal Link Expressway via Johor–Singapore Causeway). History Expansion The latest expressway completed is the 5 km Marina Coastal Expressway (MCE), which links the East Coast Parkway and Kallang-Paya Lebar Expressway to Marina South and Ayer Rajah Expressway and includes Singapore's first undersea tunnel. Construction started in 2008 and the expressway opened to traffic 29 December 2013. Prior to construction of the Marina Coastal Expressway, the Kallang–Paya Lebar Expressway which runs for 12 km, 9 km of which are 10 m underground, was started in 2001 and a 3 km section linking the Pan Island Expressway and East Coast Parkway was opened in late 2007. The Kallang–Paya Lebar Expressway was completed on 20 September 2008. Construction of the 11th expressway, the North–South Corridor, originally conceptualised as the North-South Expressway was announced on 30 January 2008. The new 21.5-kilometre expressway will cost about $7 to $8 billion when fully completed by 2026 and will connect the East Coast Parkway with the northern parts of Singapore. In 2016, the Land Transport Authority announced that the North–South Corridor will be Singapore’s first integrated transport corridor featuring continuous bus lanes and cycling trunk routes, rather than a normal expressway when originally conceptualised. Features Like all other global controlled-access expressway network, there are no traffic lights on the expressways. At an interchange with another road, an expressway is connected to it via slip roads. This allows traffic to change routes without having to stop or slow down. Due to the need to conserve space in land-scarce Singapore, there are no cloverleaf interchanges on the entire island as they are too large. Instead, traffic