The High Council for Equality between Women and Men (HCEfh) sent the report to France's Minister of Social Affairs on Thursday asking for the issue to be addressed, and promptly.
The study found that a full 100 percent of the 600 women in Seine-Saint-Denis and Essonne, two areas in the outer suburbs of Paris, said they had experienced at least some form of gender-based sexual harassment in their life while riding the train.
The Council defined "gender harassment" as "the imposition of any kind of words of behaviour that are intended to created a situation that is intimidating, humiliating, degrading, or offensive". It added that these kind of actions aren't usually physical, and hence aren't punishable by law.
It added a raft of measures for how France could address the issue, including education programmes to let women know how to identify harassment, and how to react if they are a victim. It also suggested other measures like letting bus drivers stop at undesignated stops along the route to allow women to get off closer to home, and printing the number for a complaint hotline on transport tickets.
Minister of Health and Social Affairs Minister Marisol Touraine acknowledged that the report was of a "high quality", telling French channel iTV that the government would "take action" in the coming weeks.
Margaux Collet, spokeswoman for Osez Le Féminsme (Dare Feminism), said it was high time that France implemented the regulations.
"What we need now is a real response from the government. The public are demanding it," she told The Local.
The group noted that the report was the first to recognize the "magnitude of the phenomenon".
"The problem is that harassment on public transport has basically been trivialized. The figures are shocking. It exists everywhere but its something young foreign women notice when they come to Paris," Collet added.
Indeed, one 26-year-old woman, who spoke on the condition of anonymity, said that Paris was the worst city she'd lived in when it came to sexual harassment.
"The men in Paris take a lot of liberties... it's like they don't really care what they say or how it might make someone feel," she told The Local.
"Sometimes I deliberately change train carriages if there are lots of men. I'd rather not put myself in a situation where I'm alone with only men because I know what would happen."
She said men on the Paris Metro will often change seats to sit next to her and start a conversation, leaving her feeling cornered.
Sometimes, it's not just words. She explained that one man who appeared drunk grabbed her arm and then her bottom.
"I didn't report it, I just went away. I'm kind of used to it in Paris. It's not like this anywhere else I've been."
Ernestine Ronai, a spokeswoman at the High Council, said that women needed to learn to realize when they were the victims of crime
"Women don't know how to put these ordeals on public transport into words," she told newspaper 20 minutes.
"Touching somebody's buttocks is sexual assault and punishable by five years in prison and a €75,000 fine."
She added that it was important to remind witnesses that they are also responsible to help, pointing to a case in Lille, northern France, where passengers stood by while a drunken man sexually assaulted a mother of four.
Have you been a victim of sexual harassment on the public transport system in Paris? Contact us: firstname.lastname@example.org