Ride-hailing companies catering exclusively to women are cropping up and raising thorny legal questions, namely: Are they discriminatory?

In Massachusetts, Chariot for Women is promising to launch a service featuring female drivers picking up only women and children. Drivers will even have to say a "safe word" before a ride starts.

Michael Pelletz, a former Uber driver, said he started the company with his wife, Kelly, in response to instances of drivers for ride-hailing services charged with assaulting female passengers. Pelletz believes his business plan is legal, and he's prepared to make his case in court, if it comes to that.