Flirting: How should I respond when someone plays eye-tag with me in a traffic jam?
"I'm going to assume you are a male who wants to form a connection beyond eye contact in this situation.
The key is to openly acknowledge the moment you are sharing. Perhaps on the second glance, when it is obvious there is mutual interest, smile and wave at her. This will force a response, which will likely be one of three things: waves back / laughs (positive response), smiles nervously and looks away (ambiguous response), or coldly turns away (negative response). In the case that you receive a negative response, wait for her to look again and do something funny, e.g. make a silly face. That should elicit the positive response you're looking for.
If you really have been playing "eye-tag," you will most likely receive a positive response (or an ambiguous response if the woman is shy or caught off guard). Once this happens, you can ask for her phone number. Signal for her to put her window down. Then say something like, "Hey, I know this is crazy, but I think you're really cute and I will kick myself all day if I don't ask for your number." In this situation it is acceptable to ask for a woman's number right away. She will realize the moment is rare and it will disappear soon. Also, she will feel comfortable interacting with you from the safety and distance of her own vehicle. The key is to smile and to come across as fun and spontaneous.
And if you have to hold up traffic a little bit, do it. It will be worth it." -Matt Levene