Except he didn't propose women only carriages did he.
“It is unacceptable that many women and girls adapt their daily lives in order to avoid being harassed on the street, public transport, and in other public places from the park to the supermarket. This could include taking longer routes to work, having self-imposed curfews or avoiding certain means of transport.”
“Some women have raised with me that a solution to the rise in assault and harassment on public transport could be to introduce women only carriages.
“My intention would be to make public transport safer for everyone from the train platform, to the bus stop to on the mode of transport itself. However, I would consult with women and open it up to hear their views on whether women-only carriages would be welcome - and also if piloting this at times and modes of transport where harassment is reported most frequently would be of interest.”
So he is prepared to consult and discuss something that has been raised with him by some women - obviously a dreadful person that he doesn't impose his view but is prepared to discuss.
Personally I don't think these would be the answer - they were apparently last used in 1977 - but I am very glad he is prepared to look at all solutions.