Fixing something is usually done by putting the resources towards the right place. One attempt might be to build more roads in the attempt that this will reduce the amount of traffic jams. But the most efficient resource allocation is done at a different location, namely the railroad system. Similar to the car roads, the train system in india has a high demand but low amount of ressources. And building new railroad networks is expensive. A cost effective alternative is to measure the existing traffic with more sensors.
So a cheap version to improve the efficiency is to buy a simple arduino based sensor and count how many trains are arriving at the trains station and how many are leaving. Also the sensor counts the time and date.
Such a single sensor won't be able to fix all the problems of India, but it is a first step towards a possible solution to the traffic jam problem.