This could be a infrastructure stimulus project that helps millions of construction worker (railway construction for the most part) stay employeed. And it will also help alleviate the pressure of highly populous capital metro: skyrocketing real estate market (due to supply-demand imbalance), traffic congestion, garbage processing, food/water supply, all become a big headache when Beijing has to support 23 million people (probably more if you count those unregistered migration workers etc.)
