First of all, there are almost no 18 year olds without a driving licence or passport, as they generally need one or the other to purchase alcoholic beverages, cigarettes and/or vapes. Things are much stricter than when I was a kid. It's even common to get a provisional even if you have no intention to learn to drive, though obviously some are excluded from holding one on medical or criminal grounds.
Do you actually have facts and figures to back this up?
No facts and figures, I am afraid, just my experience. Apologies for taking time to respond, I wanted to think this through overnight in case I missed a cohort.
Until about 10 years ago I was Course Director and Tutor for HE programmes at an FE college, a post I held for more than a dozen years. Our catchment area was predominantly inner-city Birmingham; the majority of our students were of south or southern Asian descent. In these roles I would almost certainly have known who had applied for a college parking permit, I also gave out application forms for student West Midlands Travelcards, the majority asked for those (and some already had them). I can think of very few women who held a parking permit, none of which were south Asian. I knew they travelled on the bus (or, in some cases, train) because so did I - I saw them or could tell them how to get to places if they asked, I also know that a significant number had to use more than one bus (from the area they lived in). Of those women (of other backgrounds) that held a permit, the majority were classed as mature students and one was disabled. Amongst male students, it was a little less cut and dried, some did have cars (for instance, one worked overnight) but it wouldn't be half (I should add, one gave me a lift once).
This is, of course, one part of the country in one setting. And I was aware of particular parts of the city where 'boy-racers', either in cars or on bikes, could be found (even then it would be foolish to suggest all had a full licence). It could be that access to public transport was a reason for choosing the college. However, through talking to some parents and religious leaders I would be surprised if 'learning to drive' was high on the list of skills they wanted these female students to acquire. They may eventually have needed a passport though.