[xoxoxoBruce]

I haven't found the headlights to be effective in daylight.
You only screw up the flow of traffic in the lane next to you if it's packed so dense everybody is crawling. Traffic doesn't move in a continuous flow, it moves in packs, mobs, with breaks in between. One of the things I noticed a very long time ago, before mobile radar, and used it as a defense strategy. If a car is coming up fast from the rear in the left lane, and passes a group of three or more cars in the right lane, if not one of that group pull out to pass after he goes by them, it's a cop. Now that strategy is outdated, but traffic habits haven't changed except to add more clueless dolts who are now distracted as well. Oh, and there's more angry armed people out there.

There is no line, there is no fast enough. Travel at what's comfortable for you, but always have situational awareness and let faster traffic by.

Two rules of the road:
1- Don't hit the car in front.
2- Don't impede the car behind.
Then you will live long and prosper.