The state-run railways and private luxury lines give full view of the country's people as well as its sights, Rajesh said.
"You could be in first class with ambassadors and politicians in these air-conditioned compartments" she said. "Go down to the other end, you'll find people sitting on wooden slats."
"No one is excluded," she added. "For every price, anyone can travel."
Below are edited excerpts from a conversation with Rajesh on how to navigate India's railways.
Q. India is enormous. How do you start planning an itinerary?
A. Before you go, buy an Indrail Pass, which is available only for foreign tourists, at a travel agency. Indian Railways, the state-owned network, has so much ticketing bureaucracy. You can avoid it with the pass, which allows for unlimited travel for up to 90 days. All you have to do is make reservations for the seat at the station. It's worth the investment: At the time, I paid $530 for 90 days.
The official website of Indian Railways is awkward. For figuring out your itinerary, I recommend ClearTrip.com and IndiaRailInfo.com, which lists every single train that goes to your destination, all the prices, all the classes and how long they take. Let's say you want to go from Delhi to Jaipur; you could take a four-hour journey for about $10 on one of the day trains like the Shatabdi Express or the Duronto Express - they're fast, no-nonsense, clean. Or you could take a train that costs 50 cents, but it's nine hours in an uncomfortable compartment.
Q. Any particular itineraries you recommend?
A. Many tourists do the Golden Triangle in Rajasthan - Delhi, Agra, where the Taj Mahal is, and Jaipur - and the private luxury trains are good for exploring that. I took the Indian Maharaja-Deccan Odyssey from Mumbai to Delhi and saw the Maharajah palaces, a tiger sanctuary, the Ellora and Ajanta caves. There's also the Maharajas' Express, a new premium luxury train, with Swarovski crystals and such.
And in the south I took the Golden Chariot in Karnataka from Mysore to Vasco da Gama. Goes through lesser-known areas and palaces, but no less impressive. These trains are expensive, but I've never seen anything quite so fabulous. Really strange to sit on an exercise bike in a gym, in a train, and it's all moving past you.
Q. Any favorite routes of the public train system?
A. I loved the one through Bangalore and Mangalore called the Green Route because it's so lush, especially post-monsoon season. The Konkan Railway from Mumbai to Goa has the Arabian Sea on one side, the Sahyadri Mountains on the other. It goes quite slowly, so everyone gathers in the vestibule, the doors always open. The train squeezes through mango groves, tiny villages; you can look to someone's house, smell what they're cooking.
Q. Any advice for female travelers?
A. I recommend asking for the upper berth, the top level in a sleeper compartment. You're out of reach of wandering hands, and it's good if you like napping during the day.
I traveled mostly with a male photographer, but I did go off on my own for a month and I was absolutely fine. As soon as they found out I was alone, families would invite me into their compartments. People are very welcoming to tourists. That's the nice thing about trains: You're with these people for an hour, two, maybe 24, and you come away with all of this local knowledge.