Someone once told me: Always ask the prettiest girl in the room to dance, because no-one else will.
I'm not suggesting you dance with her, but I'd be arranging to pull up alongside her at traffic lights and open with "I feel like I should introduce myself seeing as I pass you every morning. I'm Kit…"
You've already got a bit of common ground, so "How far do you commute?" wouldn't sound too prying.
Follow that up with a few cheery "Good morning [insert girl's name here (not just any girl's name)]" which should just about tee things up for your big finale, again at traffic lights…
"Morning [xxxx], this is my last commute as I'm moving jobs (or whatever)… I hope this doesn't sound too forward, but do you fancy a drink sometime?"
Bingo. If that doesn't work, she's a lezzer.
Edit: And if she has a tongue like the young lady above, ask for her thoughts on tubeless rims.