Expressways of Singapore
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The expressways of Singapore are special roads allowing motorists to travel quickly from one urban area to another. All of them are dual carriageways with grade-separated access. They usually have three lanes in each direction, although there are two- or four-lane carriageways in some places. There are eight expressways, with another one, the Kallang-Paya Lebar Expressway, currently under construction. Studies about the feasibility of additional expressways are ongoing, though it is unlikely that there would be another expressway after the KPE.
Construction on the first expressway, the Pan Island Expressway, started in 1966. The other expressways were completed in stages, with an extension of the Seletar Expressway being the most recently completed, in 1999. Today, there are 148 km (92 miles) of expressways in Singapore.[1]
The latest expressway under construction is the Kallang-Paya Lebar Expressway which runs for 12km, 9 of which are 10m underground. Construction started in 2001 and a 3km section is to be open in late 2007. It is expected to be completed by 2008.
[edit] Features
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. Instead, traffic efficiency and land space are maximized by having traffic lights on terrestrials roads, as well as the usage of interchanges such as Stack interchanges. The most common forms of highway-road or highway-highway intersections are SPUI, diamond and trumpet.
Certain types of transport, such as pedestrians, bicycles, and learner drivers, are not allowed. The speed limit is usually 90 km/h (56 mph); however, the old limit of 50 mph (80 km/h) still applies at certain stretches. Speed cameras are used to enforce these limits.
The road surface is asphalt, unlike normal roads which may have concrete surfaces. The lanes are separated with white dashed lines, while unbroken white lines are used to mark the edges of the median and shoulder. The shoulder is reserved for stops due to breakdowns and emergencies, and motorists are prohibited by law from travelling on it. Lanes are numbered from right to left, with lane 1 being the closest to the median. Crash barriers, cat's eyes and rumble strips are also used to ensure road safety.
There are signs marking the start and end of an expressway at its entry and exit points respectively. The Electronic Monitoring and Advisory System is used on all the expressways — cameras are used for live monitoring of expressway conditions, and LED signboards display information messages, such as warnings of any disruptions to the normal flow of traffic, as well as estimated travel times. The Bukit Timah Expressway is part of the AH2 Asian Highway Network. The longest expressway, the Pan Island Expressway, is only 41km (25 miles) long and therefore there are no rest areas.
[edit] See also
[edit] References
- ^ Expressways in Singapore: Did you know?. The Highway. Automobile Association of Singapore (July 2001). Retrieved on 2006-04-05.
