I saw an interesting bit in the online Yated last week regarding the expansion of the Mehadrin (sex-segregated) bus lines in Israel.
Now, I personally find the idea of having women sit in the back of the bus repugnant. However, I also have to take into account that I am an American and "back of the bus" has an ugly connotation here that does not exist in Israel. Furthermore, I have to keep in mind that we're dealing with people who have a completely different mindset than I do. As such, as long as a substantial portion of the population wants sex-segregated buses and as long as a deal for it is negotiated fairly, I don't have a real problem with it.
However, there was a line in the article that I found quite interesting (bolding mine):
The rabbonim said they have been discussing various matters with Egged and Transportation Ministry representatives in order to make special arrangements that meet halachic requirements.
I know, from personal observation here in New York City, that there is no halachic requirements to have segregated seating in public transportation. Thousands of frum Jews take mixed-seating buses and trains everyday with nary a second thought. No one thinks that they are engaged in anything licentious by taking public transportation and I don't think that any of them ever asked mechila (forgiveness) from God on Yom Kippur for taking public transportation.
If you like, you can certainly argue that having separate seating buses and trains is a halachic extra that one should strive for. (I'll probably disagree with you, but the argument isn't totally out of the ballpark.) You could argue that perhaps a man won't see an immodestly clad woman if the seating is separate (although he does have to face the back of the bus as he walks to his seat, doesn't he?). But one thing that I think we can all agree on is that it is not a "halachic requirement." It never was and still isn't to this day. By calling it a "halachic requirement," all the rabbonim are doing is engaging in creeping standards.
Now, to be honest, creeping standards are not always a bad thing. After all, the standards for health care are far more stringent today than they were a hundred years ago. This didn't happen overnight either... the standards "crept" upwards as the century dragged on. Education standards grew as well -- many more people living today (expressed in terms of a percentage of the population as a whole) have college educations than those living a century ago. Our physical standard of living has increased as well.
Religious standards increase over time as well. A century ago, many Orthodox children in the United States sent their kids to public schools, and taught them Torah subjects after school. Today, most Orthodox children attend yeshivos where they receive at least (and in many cases much more than) a half-day of Torah education.
However, there is an important point to be made with regard to the last item: the increase in standards has been voluntary. Orthodox parents have *voluntarily* sent their children to yeshivos in the United States. No one (to my knowledge) has been forced to. People are still free to send their kids to public schools and educate them in Judaic studies in the afternoons or evenings. True, there are very few who do so, but the option is still there if they want it. No one is being forced to do so.
However, there are times when creeping standards are a bad thing, even if the standards are creeping higher. Sometimes the higher standard comes at too high a cost. There is even a term for this in halacha -- it's called a g'zaira sheain hatzibur yechola la'amod bah -- a decree which is simply too hard for the community to keep. Such a decree, even if it embodies higher standards that, in theory, one should strive for, is null and void, because the cost (and I don't just mean the economic cost) of keeping it is just too high for the community. An extreme example of this might be a decree that all men quit their jobs and learn full time. Such a decree would be impossible for the community to fulfill and therefore, would be null and void.
The needs of the community must be balanced against the desire to have increasing standards of observance. Sadly, however, it seems that the needs of the community are often not considered when decrees are issued; especially when those decrees are extra-halachic. A good example of this, IMHO, was the decree against women's education programs in Israel a few years ago. Not only were these programs shut down, but women who had already completed them found themselves shut out of the education jobs that they were trained for. It's one thing to say that these programs are bad (which is a position that I don't agree with), but it's quite another to then take people who already completed the program b'hetter (while it was permitted) and cause them to be blacklisted because of it. Many women who were probably the sole wage-earners in their families (because their husbands learn full time) were out of jobs. Why? Because of an extra-halachic decree. This is a case where the needs of the community were not considered before the decree was issued. Another example was the ban on certain colors or styles of clothing in Israel. The ruling was clearly extra-halachic - there is nothing wrong with wearing red clothing or certain styles - but there was absolutely no consideration made for merchants who carried such merchandise and bought it in good faith. They were simply told to get rid of it, or face a boycott.
And so it goes. If you want to make a decree on something that is not strictly halacha, then consider the needs of the community -- but also point out that the decree is extra-halachic. But don't try to pass off your own personal chumros (stringencies), such as separate-seating in mass transportation, as halacha. At least be honest about it.