Having read Phil W's account of the Windsor Chester Windsor (which I also did), he mentioned 'Howard was battered and bruised, his face was was swollen and cut, he had properly crashed when he fell asleep on the bike, broken his helmet in four places, bloodied knees, his ribs hurt, ripped his jacket'. This is a serious concern for me on long audax rides as I can say that it has nearly happened to me on several occasions. I was OK on WCW as I had 2hr 45min sleep at the appropriate control and I didn't suffer with the dozies at all.
However, the London Wales London (400) was a different matter. After the last manned control and predawn I suffered terribly and there were certainly 4 or 5 times when I suddenly thought 'I was asleep then', but somehow regained control before the inevitable crash. Even though it was freezing cold (which you would think would keep you awake), listening to music and standing on the pedals, nothing would stop me drifting off.
I know people say, 'just have a 15 minute power nap in a ditch', but when it is near zero degrees and everywhere is wet at the same temperature, it is not practical to simply lie down in a field and get some sleep. So, what are other's recommendations for combating the dozies? I have tried caffeine tablets and they do not seem to have any effect on me.