Titles are obsolete IMO. What are they for? A name is enough to identify a person, surely. But a title which automatically announces women's sexual status to strangers, particularly when those titles are all a truncation of the same word of 'mistress', does seem very archaic and pointless in this day and age.
A 'Dr' title neatly circumvents the problem for me, but women should not have to complete a PhD to exercise such a 'privilege.' I'm okay with Ms, but prefer Dr as this doesn't announce my sex or status. The French and German custom of Mademoiselle/Fraulein reverting to Madame/Frau when females reach adulthood also sounds sensible to me. I'd accept 'Mrs' were a similar custom to be adopted here (but not unless).
As a married woman who has always used my own family name I've been quite surprised at the ferocity of reaction (only ever emanating from other women, funnily enough) to this idea. Attempts to put me back in my box have been quite unexpected. Retaining one's own identity on marriage isn't that unusual. Beats me why any stranger would give a fluffy fuck how another stranger was styled when all they want is to tick a box. My MiL persists in addressing my by Mrs Hisname, which she knows fine well I've never used, despite polite requests to respect my actual identity. I've even received a (very wrong) assertion that I don't 'respect' my husband. Our respect is mutual.
Where passenger safety is an issue, it becomes more pressing. A default adult female identity is a good idea (I have no problem if this happened to be Mrs for everyone). The argument that this removes 'choice' is a little odd, as there is nothing stopping people from replacing this with another preference should they so choose.