What kind of seat would you like? Smoking or nonsmoking? Cell-phone or non-cell-phone? Seated or standing harnessed to a board? Groping or non-groping?

Single-gender mass transit, already in place in Tokyo and Mexico City, reaches Rio today with the introduction of all-female railway cars, in an effort “to avert groping and other unwanted sexual advances.”

Hopefully Rio’s men won’t assume that a woman’s presence in a mixed-gender car is an invitation to grab. Anyone have experience with this kind of transit??