Somewhere the equation is wrong because the moment we start talking about urban transportation, the conversation veers towards metros.
While looking at urban transportation, you must consider cycling tracks, bus services, bus rapid transport system (BRTS), and light rails, much like you find in European cities; and then there are regional rapid transportation systems (RRTS).
A metro is just one solution that is related to the size of the city’s population. There is a popular perception that towns with less than a five lakh population don’t merit a metro. Then there are other factors, such as population density, the ability to pay, and finally the intensity of commuter traffic. All these have to be taken into account for a metro rail to be viable in a city.
Of India’s 5,400 towns and cities, about 100 require a 21st century urban transportation system. To my mind, a city like Chandigarh is ideal for, more than a BRTS, an electric trolley bus. And then, of course, a big city requires an RRTS because the pattern is linked to the model of urbanisation.