The Marina Coastal Expressway (MCE) is a road of superlatives.
When it opens to traffic at 9am today, motorists will be driving through Singapore's widest and deepest underground road.
The MCE, which joins the East Coast Parkway (ECP), Kallang-Paya Lebar Expressway (KPE) and Ayer Rajah Expressway (AYE), has five lanes in each direction. The KPE has three.
At its deepest, it is 25m below sea level. It is also the first undersea road, with a 420m section beneath the seabed south of the Marina Barrage.
The 5km, $4.3 billion infrastructure is also the shortest highway here, and the costliest, at $860 million per km.
It is also the smoothest, as its surface is finished using a laser technology that allows for no more than 2mm of undulation per metre. The only other stretch of public road surpassing this standard here is the Marina Bay Formula One circuit.
At the MCE's opening ceremony yesterday, Senior Minister of State for Transport Josephine Teo described the expressway as "a massive engineering feat".
"Piles as long as 85m, or 25 storeys, had to be driven into the ground," she said, adding that more than four million cubic metres of soil, "enough to fill more than 1,700 swimming pools", was excavated.
"In spite of all these challenges, the MCE construction team was able to complete the project on time," she noted.
Emeritus Senior Minister Goh Chok Tong and other MPs were also at the opening ceremony.
Land Transport Authority director Chuah Han Leong, who oversaw the MCE project, said "the ride is much better" than that of the KPE.
Mr Chuah also said the MCE is more watertight than the other underground expressways. It has better and tougher waterproofing than those used for the KPE and the Central Expressway (CTE).
But despite this, he said leaks might develop over time. "So we put in groutable tubes," he said, referring to tubes along the tunnels that allow a sealant to be pumped in to fill up leaks.
The MCE is also more fire-resistant than other underground roads here, in line with international standards of fire safety which have risen over the years.
It has a deluge system - essentially an oversized sprinkler system - that dispenses 350 litres of water a second.
The ceiling of the entire MCE is also lined with fire-retarding boards. The CTE does not have these, while only sections of the KPE that go under the Pelton Canal and Geylang River have them.
These boards keep the temperature of the concrete below 380 deg C, even when a fire is raging at 1,000 deg C, Mr Chuah said.
Tanjong Rhu resident Raymond Tay, 60, is one of those looking forward to using the MCE.
The yard crane operator, who works at PSA's Keppel port, said besides driving, he would be able to use bus service 30, which will ply the tunnelled road. Separately, nine premium bus services will also make use of the MCE.
Engineer George Lee, 43, who lives in Jurong East, said: "I will use it when I visit my mum-in-law. She lives in Upper East Coast Road. Currently, I use the PIE (Pan-Island Expressway) to get there."
Christopher TanThe expressway is "a massive engineering feat", said Senior Minister of State for Transport Josephine Teo. "Piles as long as 85m, or 25 storeys, had to be driven into the ground" and more than four million cubic metres of soil, "enough to fill more than 1,700 swimming pools", was excavated.