Project will be world’s longest driverless underground line when completed next year, and more lines will follow.

Yesterday, Singapore opened the first phase of its future Circle Line, which will ring the downtown core and provide easier connections among the city’s existing and future metro lines. Once completed in 2011, the circumferential route will have cost around $5 billion U.S. to construct and will run 33.3 km, making it the longest automated, fully underground rapid transit corridor in the world. The portion of the line opened yesterday, at 5.7 km, will connect the North-South (Red) and North East Lines (Purple). Singapore’s push to expand, starting with the Circle Line, will eventually double the city-state’s metro network with some of the most advanced public transportation technologies offered in the world and provide a model for other cities building such lines.

Singapore’s projects are constructed by the nation’s Land Transport Authority, which then leases out operations to two private operators. Since the country’s independence from Malaysia in 1965, it has proceeded with an ambitious urbanization scheme involving the construction of mass transit lines and large (banal) apartment housing estates. That process, in addition to an aggressive pursuit of foreign investment, has made the country the fourth wealthiest in the world by GDP per capita.

The government’s recent plans have focused on augmenting rail services, which already provide the vast majority of commutes, so that more can benefit from train service. Today, about two-thirds of transit riders rely on slower, less effective buses. Unlike the first two lines built — the red North-South line and the green East-West line, which are mostly elevated on concrete viaducts — the new projects are being constructed fully underground. As a result, they can be built with far less intrusion on the urban landscape and can operate less visibly in neighborhoods. In addition, tunneling the corridors makes full-scale automation more simple.

Indeed, the first product of this method of transit construction was the North East line, which opened in 2003. That project will be joined in 2011 by the full Circle Line, in 2016 by the Downtown Line, in 2018 by the Thomson Line, and finally in 2020 by the Eastern Region Line, doubling total metro route miles on the island to about 250 km, with an expected daily ridership of 4.6 million, slightly less than the population of the country. The Downtown and Circle Lines are currently under construction.

Singapore’s massive investment in new rapid transit is one element of the nation’s strong efforts to encourage public transportation use. Since 1975, the city has also operated a congestion charge downtown, a system that has been relatively effective in limiting automobile traffic even with the island’s increasing wealth and car ownership. In addition, the decision to build high-density, focused neighborhoods near transit stations has ensured that most people, even those far from the downtown core, aren’t isolated from the city’s urban life. The construction of more heavy rail lines will shore up missed connections.