Do we need to pass a law requiring you give your seat up for pregnant woman on the bus?

The past few days there have been some letters to the editor in Vancouver 24 hours discussing the topic of offering bus and SkyTrain seats to pregnant women. I suppose this poll question in today's paper is addressing that, though it makes me think that there is one individual who is publicly acknowledged as public transit's one pregnant woman. Of course, it could be that "woman" is supposed to be "women". Also, based on the question's intro, is Vancouver 24 hours in a position to pass this law, or any law for that matter? Maybe it's nitpicky, but a better intro might be "Should there be a law requiring..."