Even in Wales, 25% can't. This isn't a figure you can ignore.
And that's a hypothetical, it relies on landlords playing ball etc. then there's the social issues. On the north of England we have lots of terraces built for mill workers, these aren't owned by the richest on society. So then you're in the situation of charging the poorest more for transport. And these are necessarily on towns with good transport links (think 1 bus and hour).