I don’t think it is reasonable to set up exclusive carriages for women. Any feminist with self-esteem will refuse others to regard them as vulnerable as children or seniors, and require any preferential treatment because of this.
Even if I agreed women should be given such treatment, I don’t think one carriage would set them free from the unpleasantness of pushing and squeezing. In any bustling metropolis with a dense population, crowded public transportation, especially on subway lines, is a headache during rush hours. No public transportation could fulfill the needs of spending less while gaining convenience and comfort at the same time. If you want the latter, you can take a taxi but pay a higher price. Whether there is women-only carriages or not, riding the subway would be no easy experience during rush hours. The existence of such a carriage also reduces the number of carriages available for other passengers and thus worsens congestion. Besides, one carriage is not enough to hold all female passengers. Those who fail to ride on women exclusive ones have to fight even harder for a space in other carriages.