Women-only passenger cars (女性専用車両, josei sen'yō sharyō?) are railway or subway cars intended for women only. They are offered on some Japanese train lines. Egypt, India, Taiwan, Brazil, Mexico, Indonesia, Belarus<1>, the Philippines and Dubai<2>, also offer women-only train cars, while passengers in some other countries have demanded their introduction. Such cars are slated to be introduced in Seoul, South Korea in 2008<3>. In Japan, the special cars were introduced to combat lewd conduct, particularly groping (chikan). An exemption is made for men with disabilities, who may ride any passenger car.<4> First offered in 2001, all commuter rail and subway companies in Tokyo and Osaka, Japan's two biggest cities, run women-only cars.
Women-only policy varies from company to company; some are effective during rush hour, others throughout the day, while some limit women-only cars to rapid service trains, as they tend to be more crowded and have relatively longer distances between stops. But in general, the policy is effective only on weekdays, excluding holidays. Platforms and train doors are marked with signs indicating boarding areas for the cars, and the days and times when the cars are women-only. Also, most train operators in Japan allow male elementary school pupils, disabled persons, and their assistants to board women-only cars
http://en.wikipedia.org/wiki/Women-only_passenger_car