A commentaryTurkmenistan appears poised to build the one white elephant it's overlooked during a 15-year building spree—a subway system under the streets of its deserted capital city. President Gurbanguly Berdymukhamedov mooted the idea during a meeting with Ukrainian construction magnate Vladimir Petruk in Ashgabat this week. During the meeting, Berdymukhamedov reportedly asked Petruk to study the issue. "Due to the rapid growth of the capital city and increase in its population, the esteemed president drew attention to the need to build a metro," state television announced on February 4.I can't help but take a bit of credit for the concept, which I used to suggest in jest to anyone who would listen when I lived in Ashgabat. In jest, because Ashgabat's low population, sprawl, earthquakes, and lack of traffic make a subway an imprudent investment.Petruk apparently raised the idea back in 2005 with Berdymukhamedov's predecessor, Saparmurat Niyazov. The plans went nowhere that time, perhaps for good reason.Estimates of Ashgabat's population generally hover between 700,000 and one million. During the Soviet era, one million was the minimum number required for Moscow’s planners to consider building a metro in a city.While the Guinness Book of World Records says Ashgabat hosts the world's highest concentration of white marble-clad buildings, its concentration of actual residents is notoriously low, to the point where many districts feel empty. Large new apartment buildings are spaced far apart, with some units sitting empty years after completion. Massive parks, curious cultural objects – such as the world’s largest indoor ferris wheel – and vast emptiness separate residential districts in new parts of the city.A subway system requires a high-population density to be efficient. Ashgabat's wide roads were designed to suit buses and personal cars. Yet traffic is rare except when the president's security team closes a road hours in advance of his motorcade, causing the odd traffic jam. Ashgabat’s buses are reasonably efficient and cheap, as are unlicensed taxis, thanks to highly subsidized fuel.Ashgabat residents are also justifiably leery of spending time in newly constructed objects, thrown up lately with suspect standards. They would be forgiven for hesitating to travel under a city where mass graves for the 100,000-odd victims of the 1948 earthquake are still auspicious urban landmarks.Kazakhstan poses a model for failure that Turkmenistan might heed. Almaty's metro, which opened in 2011, took over 20 years to build, doesn't connect enough neighborhoods to be useful yet, and loses riders to skepticism about construction standards. Despite Almaty’s notorious traffic and much higher density, metro ridership is still low.Perhaps Ashgabat’s metro could become a link between numerous underused boondoggle projects: A new $2 billion airport will replace Ashgabat's sleepy existing terminal in 2016, and its $5 billion Olympic City, complete with monorail loop, is scheduled for completion in time to host the obscure Asian Indoor and Martial Arts Games in 2017. Of course, while we indulge in snickering at Turkmenistan’s many spendthrift decisions, profligate government waste is no joke for residents who cannot get decent medical care and whose children are conscripted to pick cotton.