Women's advocates have kicked off a campaign for safe commuting for women to mark International Women's Day.
Organisers said the campaign aimed to create an environment that allowed women to commute without facing harassment or sexual assault.
The organisers of the "Safe Cities For Women" campaign include the Thai Health Promotion Foundation (ThaiHealth), the Bangkok Mass Transit Authority (BMTA), and the Women and Men Progressive Movement Foundation.
Many women are at risk of being sexually harassed on buses and even in uncrowded public places, according to the organisers who blew whistles to launch the campaign Wednesday at the Victory Monument, Bangkok's key bus interchange point.
Participants shared their experience and cited statistics of harassment and rape targeting women commuters.
The blowing of the whistles is to send a wake-up call to the Transport Ministry to have clearer measures to protect women.
"Women should not have to deal with this issue alone," said Chari Sisawat, of the Women and Men Progressive Movement Foundation.
The campaigners agreed it is not enough to advise women to be alert to potential harm and adopt self-protection measures, she said, adding the authorities must start taking steps to build safer cities for commuters.
Bangkok has up to 217 spots that are prone to crimes, said Rungthip Imrungrueang, of the human rights group, ActionAid Thailand, citing numbers compiled by the Metropolitan Police Bureau. This reflects an unsafe environment, especially for women, she said.
A recent survey of 1,500 women in Bangkok and its neighbouring provinces by ThaiHealth also found many women "feel unsafe" mostly when they have to walk into a quiet soi or alley or a small street off the main road.
Similar feelings are experienced when they take taxis and buses, according to ActionAid.
"One third of them admitted they faced sexual harassment while walking or using public vehicles," said Waraphon Chaemsanit, of ThaiHealth.
According to the survey, 26% said men had spoken to them with sexually vulgar words, followed by 18% who said they were looked at in a sexually suggestive way, while 17% admitted they were touched by strangers and 1.6% said they were raped while commuting.
Also, the survey showed 38% of those harassed while commuting said they opted to keep silent, saying they were too shy to complain to police and did not know whether laws could adequately protect them, Ms Waraphon said.
Public buses are also viewed as a high risk area. Women are often jostled by men even when they are not in a crowded bus, said Yong Chimphli, a fare collector for a state-run bus in Bangkok, adding this is just one of many acts of molestation.
A university student, who asked to be named as "Mos", said she has been encountering such harassment since junior high school.
Without elaborating, she said one incident took place on a bus, another on a motorcycle taxi which took her into a narrow, quiet soi, and the third occurred at a bus stop where a man masturbated in front of her.