Try to outrun/outdrive him first.
If I was sure the road rager was trying to ram me and that was the only viable option due to the positions of other vehicles, that may be the only course of action. Letting him get past you may give you the tactical advantage though. Lots of options in this situation.
They don't teach single hand racking the slide anymore...........................I would be curious to know what it is, though, and wonder if it was actually a procedure specified in the manuals or just an instructors "extra knowledge"
I guess for a lot of instructors it would just be extra knowledge, depending on the level of instruction they are trained to administer. The liability involved in teaching concealed carry presentation, much less one handed weapons manipulation, requires a somewhat advanced combat pistol instructor.
I believe the earliest use of one handed racking started out with the old M1917 holster with personnel carrying cond 3. The pistol is partially drawn and the grip is turned 90 degrees with the top of the slide towards the body. The pistol is then pushed in toward the body then downward. The rear sight digs into the flap of the holster, holding the slide captive as the grip frame moves downward. The pistol is then quickly drawn upward effectively chambering a round and the presentation to the target is continued.
This method was further modified by using anything available that could capture the rear sight with enough of a purchase to cycle the pistol.
All the Gunners Mates I have talked to that were active during the era of the .45 in standard service knew this technique, but I do not believe I ever asked them where they learned it.
Kind of long winded on this, but you asked and I felt the least I could do was provide a reasonable explanation of the technique.