THERE ARE no strangers on a train when you ride the rails in developing countries.

In the cheap seats you'll be crammed close to locals and mounds of luggage in steamy-hot, clickety-clack carriages.

In Bangladesh and other South Asian countries, men ride outside on some trains, clinging to the rooftops of packed carriages. Food vendors leap between trains at stations, clutching their baskets. Inside, harried moms dole out snacks, and small children curl up in overhead luggage racks to sleep. Soot wafts through windows opened to the hot wind.

Foreign backpackers join the crowd in low-cost carriages. But many tourists exploring India or other South Asian countries by train go by "A.C." class — seats or overnight berths in air-conditioned carriages.

Even in top-class train carriages, you'll be far from alone in such crowded and socially gregarious countries. You'll just be chatting with seatmates in cooler comfort.

Kristin R. Jackson is the editor of The Seattle Times' NWTraveler section. Contact her at kjackson@seattletimes.com.