Rima Singh, an executive with an Indian outsourcing company, smokes, drinks and dates boyfriends in New Delhi --- but doesn't tell her parents back home in small-town India. Three years ago, the 24-year-old left what she described as a mundane life full of strict social conventions in the town of Mathura in northern India and headed for the bright lights of New Delhi. "Back there, falling in love is a big crime and expressing yourself is still labelled as a rebellious streak," she told AFP. "Wearing skimpy clothes, smoking, drinking, having boyfriends are all a strict no-no," added Singh. In the Indian capital, a mixing pot of 14 million people, she says she feels liberated from some of the traditions that would restrict her freedom when she lived with her wealthy but conservative Hindu family. At home, she was barred from entering the family kitchen and had to sleep on a cotton mat when she was menstruating, during which time she is considered to be impure. Tired of putting up with these "ridiculous" diktats, she and her cousin moved to Delhi on the pretext of studying computer science. She opted instead to take up a job with a private IT firm. "The decision to move to Delhi was the best thing I have done so far," says Singh who lives on her own in a small one-room terrace house -- something unthinkable for Indian women of her background in previous generations. "I am my own master here," she told AFP. Singh's story reflects deep social changes underway across Asia because of rapid urbanisation that will see hundreds of millions move to urban areas in the next decades. The population of Indian cities alone is forecast to grow from an estimated 340 million people now to 590 million by 2030, according to a report from the McKinsey consultancy published last year. "Cities are the first to embrace many concepts that are a taboo in towns and villages," says Sandhya Patnaik, a sociology professor at Delhi University, referring to pre-marital sex, live-in relationships or divorces. "Anything new or modern touches cities first. Trends percolate to smaller towns at a very slow pace." Occasionally in India, the battle between village tradition and liberal city culture can have deadly consequences, such as the "honour killings" seen in Delhi's migrant areas. In a country where arranged marriage is still the norm for most people, horrific stories of women being killed by family members over their plans to marry "unsuitable" partners are a regular feature of Indian newspapers. But experts say cities across the world generally serve as a positive melting pot, where different cultures intermingle, encouraging tolerance and the interchange of ideas. "The freedom in a big city comes from diversity," Jirapa Worasiangsuk, a sociologist at Thammasat University in Bangkok, told AFP. "It's the choices and the opportunity to choose that make Bangkok or other big cities a better place. "People have more choices to choose how to live, to choose their career, to do whatever they want." In the Indonesian capital Jakarta, 22-year-old Nani Yuningsih works as a domestic help and says city life has empowered her. "All my childhood friends got married young, mostly at the age of 15. I am the only one who's still single," says Yuningsih, who moved to Jakarata from a village in Brebes district of Central Java province at the age of 13. Despite the daily grind, Yuningsih says she disapproves of women depending on their husbands for economic support. She is attending evening classes to get her high school certificate.  "People in the village always belittle me for being single at my age. For them, it's a nightmare and shameful for women to marry late," she said. "They also laugh at my plan to study at university, saying that I'm already old and have to raise children instead." Tran Thi Ninh, a 48-year-old from a province outside the Vietnamese capital Hanoi, says her experience of city life has brought more independence, but also a sense of dislocation and a loss of identity. "The community spirit in the countryside is so tight, not here," Ninh said, explaining that the entire village would try to help out if someone fell sick. On a recent afternoon, her husband suddenly needed to go to hospital but Ninh could not find anyone to help. "They were busy with their jobs," she said of her neighbours. Sociologists say the freedom of cities often stems from a feeling of anonymity -- but this can often tip over into loneliness. The Indian executive, Rima Singh says she often feels New Delhi is an isolating, cold-hearted sort of place. "I have chosen this life but whenever I feel miserable I go back home to be with my parents," she said.