Chennai is a pulsating metropolis with millions of inhabitants, a port city and capital of the Indian state of Tamil Nadu. As with many large cities in India, the city has experienced rapid population growth in recent years and the need for infrastructure is correspondingly high. One solution to deal with the high traffic volume in the heavily built-up city is to move it underground. The Chennai Metro was opened in 2015 and so far has two lines with a total length of approximately 46km.