dead slow

 
I must pass this sign all the time, but only today while walking did I notice it. I am not sure what is meant by "dead slow". It could either mean, people have died, so go slow or you must drive so slowly like being dead! Not one of the drivers around there were paying the slightest bit of attention to it thats for sure - they all were racing down the road like they were in the daytona 500!