Drive Friendly

Scene: You're in crazy traffic. A car one lane over and just ahead clicks on its turn signal. You make space. They hesitate. You wave them into the space you've created in front of you. The car slides in ahead of you and its driver waves a thank you (usually with their right hand, just under their rearview mirror).

What happened to this tiny exchange? I've been actively seeking it out for months and am sad to say the thank you wave looks to be extinct or at least seriously endangered. This isn't a matter of national security or cause to alarm environmentalists or anything, but I miss it. That small detail made the roads nicer or at least friendlier.