There is now a range of five dollar bike helmets, partly supported by advertising. You can buy them from vending machines close to the public bike stands, or at 7/11 stores. Of course that makes it hard to justify charging $600 for a high end versions of the same lump of foam.
Edit: also some people have started to leave their cheap helmets with the bikes when they are finished with them, so you don’t always have to buy one.
Edit2: Its part of a general problem here that the people who build bicycle facilities don’t actually ride bikes, and therefore don’t see obvious problems with their designs. It took years for the helmet problem to be addressed, and the general impression is that the operators are perfectly fine with their customers breaking the law by not wearing helmets.
