In Jakarta there was a traffic regulation (appeal?) specifically to motorcycle users and their passengers. in addition to requiring riders to wear helmets, it also advised that passengers must sit astride on motorcycles (both men and women) to maintain balance for for the sake of safety. Logically, we can understand this. In any case, women who sit astride while riding as a passenger do so wearing buttoned-up clothing at the back of the motorcycle. So, don't trump up reasons like "to look like they adhere to sharia" while compromising safety. We Indonesians have our own character, there is no need for us to be herded into another culture that is not necessarily suitable.