Gender bias in data collection. Manuela Saragosa speaks to Caroline Criado Perez, author of Invisible Women: Data Bias in a World Designed for Men, winner of the Financial Times business book of the year. Why are there no female crash test dummies? We ask Lotta Jakobsson from the Volvo Cars Safety Centre in Gottenburg in Sweden. And The BBC's Stephanie Hegarty on efforts to steps to make the city of Barcelona more women-friendly.

(Photo: Crash test dummy heads on display, Credit: Getty Images)