WORK on Singapore's 10th expressway, and its most complex and expensive one to date, started yesterday.
The Marina Coastal Expressway (MCE) is meant to deal with traffic expected at the new attractions, offices and residences going up in the Marina Bay area.
These include the new integrated resort, the Gardens by the Bay and the Marina Cruise Centre at Marina South.
With five lanes in each direction, it has the capacity to move up to 10,000 cars per hour each way, compared to the 6,000 cars per hour each way on the Kallang-Paya Lebar Expressway (KPE).
Once completed in 2013, the MCE will link the KPE and East Coast Parkway (ECP) in the east, and with the Ayer Rajah Expressway in the west.
Motorists who are not headed downtown can also use the MCE to bypass the Marina Bay area.
There will be four exits and four entrances along its 5km length.
To ease congestion, the ECP stretch just after Benjamin Sheares Bridge will be converted into a network of normal arterial roads to serve the area. Currently, this portion of the ECP splits the Marina area into two unlinked sections.
Said Transport Minister Raymond Lim at the launch of the mammoth project yesterday: 'The MCE will be a valuable addition to our expressway network. It will improve our road connectivity and help to support the future development of our city.'
Of its 5km length, 3.6km will be underground, including a 420m stretch parallel to the Marina Barrage which will duck 20m below the mean sea level.
It will be 120m wide at some points, almost three times the width of the KPE.
The project is so massive that civil works have to be carved up into six portions so that the construction crews are not overstretched.
So far, the cost of the project has come up to $4.1 billion - far exceeding the $2.5 billion estimated in 2007.
In comparison, the 12km-long KPE, which has 9km of road underground and some parts under the Singapore River, cost $1.7 billion.
The Land Transport Authority (LTA) said that it considered alternatives like building a network of bridges to link the area, but decided against it as it would 'devalue' property in the area and 'look messy'.
Reasons for the high costs include:
- Large-scale excavations of up to 25m deep and 120m wide;
- Difficult soil conditions - the soil is made up mostly of soft marine clay;
- The need to drill up to 59m - or 20 storeys - in some areas of the seabed to get to solid ground for piling work;
- Reclamation of 13.1ha of land at the Marina Wharf and Marina East area;
- High raw material costs when tenders were awarded. A clause in LTA's contracts ensures that if raw materials are purchased by contractors at lower prices, the Government will be reimbursed the difference; and
- The cost of Electronic Road Pricing gantries at the entrances and exits, which is included in the construction cost.
Despite the technicalities of the project, Mr Lim assured the public that all work will be done safely.
Among the safety measures employed for the MCE is an SMS alert system that will send continuous alerts to engineers on data like ground movements that is collected and analysed on a regular basis.
Professor Robert Mair, who is on an international panel of consultants called in to review the MCE, noted that the complexity of the project was 'right up there with the toughest in the world'.
Similar projects include Shanghai's Yangtze River tunnel and Japan's Tokyo Bay Aqua Line.
The head of civil and environmental engineering at Cambridge University added, however, that LTA is well-equipped and experienced to handle this project.
Said Prof Mair: 'Looking at their robust structures, soil investigations and monitoring systems, they have taken on board the lessons learnt from Nicoll Highway.'Source: Straits Times, 29 April 2009