Why Metro Rail in Kathmandu?

The Kathmandu Valley now shelters an estimated population of around four million when both permanent and floating residents are counted. This places it among the densest urban areas in the world. However, road infrastructure, the lifeline of the urban system, is grossly inadequate in Kathmandu Valley. Most world cities allocate fifteen to twenty five percent of urban land to roads. But only about five percent of land in the valley is used for roads, which is probably the lowest proportion among national capitals.Even Asian cities like Bangkok and Jakarta, both infamous for congestion, have managed to set aside around eight percent of their area for road space.