Really?
I don't know how tall this woman is, but this doesn't seem to be an issue like you say it will be.
Regardless, I don't agree with the idea of non-labeling the streets. Judging by gweed's map, it certainly looks to be possible to name everything that is necessary. The map can even be made to be a lot wider.
Those pictures are pretty interesting. Yes, I don't think it would be much of an issue, especially considering that people are frequently standing over top of people sitting on packed trains anyway. Many cities have the full system map in that location on a train, including NYC and Boston (and NYC's map is a whole heck of a lot more complicated than Toronto's). It's really just a supplementary info map that people who are transferring onto multiple lines would be using. People who are staying on the same line would just use the line map above the doors.