I should have started with: I use a 4 gpm and a 5.5 gpm machine, and a ww classic to surface clean. my classic has two nozzles not 4 so guys with a 8 gpm and 4 nozzle surface cleaner may not have the same issues as I did. I thought the same thing as you @Racer. How could this be any for efficient.
If I walk up a driveway turn and come back I will have stripes, if not that day once is starts to get dirty again the stripes will be noticeable. I tried going back over the drive way again perpendicular to my first pass and that works but is way to time consuming to do a driveway twice. I always pretreat but I tried post treating with straight SH down streamed and it still wasn’t perfect and also took more time.
If I use the method I stated in my previous post I can move the surface cleaner back and forth quickly as I move left or right. You don’t have to use the same pace as you do when you walk forward. I found it is actually quicker than walking the drive then doing it perpendicular. If you and your customers don’t mind the striping then don’t worry about it but it works and it is faster.
Again this is for smaller machines and 2 nozzle surface cleaners. I don’t do large commercial lots and I don’t use heat. For those who it applies to try and see how it works for you. I did and I was surprised.