One of the cheapest yet easy modes of travel in Chennai is by share auto. If you are ready to sit a little cramped in a space for three seats as the fourth seat you will do well. Be also prepared to hear the colorful language of the drivers. Also don't expect a very safe driving. The fares are very economical. Typically a 5 km journey will cost you just 10 bucks. A 15 km ride would cost about Rs.35/-.
The best part is the various types of co passengers you will meet. You are likely to encounter young college kids chattering away, some reading, some with earphones clamped onto their ears, young mothers with infants in arms, school children sharing toffees with their friends, the occasional drunk man, some office types who pompously talk loudly on their mobiles, housewives with vegetable laden bags and several such people. A share auto rider comes from all classes. I have seen middle aged ladies praying and chanting. One most common site is whatsapping and gaming..