Question for The Drivers

Lately it's been getting darker than usual, so headlights come on a bit earlier this time of year. I've also noticed that everyone is overzealous about the use of flashing their brights in NoVA which makes it hard to decypher what is being communicated. So I wanted to reach out to the community at large.

Yesterday I was traveling to Reston from Fairfax during rush hour to pick up a friend whose been having some trouble getting around. I was making a left turn from HunterMill to Lawyers and as I was turning, someone in a white SUV style car in the right turn lane opposite of me on Huntermill started rapidly flickering their brights at me. I flicked my brights back to communicate that they weren't on, and that was the end of the interaction.

I'm not entirely sure if my assumption of the issue was correct. Does anyone know what else could have been the issue here? I had the turn light. My brights were off. I stayed in my lane for the turn. There weren't any hazards or police on the road as well. So I'm still confused on why someone would do that.

Were they telling me to turn my brights on? I know there are a crapload of deer out this time of year.

It's just bugging me, and I really don't want a repeat of this incident as my eyes took a beating from the rapid flickering. So I'd appreciate any thoughts on this.