100 Women: Why I didn't report sexual harassment on the bus
Sian Lewis is a sociology expert who researches sexual harassment on public transport.
She was recently harassed on a bus and decided not to report it to the authorities, despite hearing many stories from women who say they are glad they spoke out about it.
Video journalist: Joe Inwood
BBC 100 Women names 100 influential and inspirational women around the world every year. In 2017, we're challenging them to tackle four of the biggest problems facing women today - the glass ceiling, female illiteracy, harassment in public spaces and sexism in sport.
With your help, they'll be coming up with real-life solutions and we want you to get involved with your ideas. Find us on Facebook, external, Instagram, external and Twitter, external and use #100Women