I recall an instance when despatching. I had a drop in East Anglia and met local fog which slowed me down to 20mph - that was the speed at which I could see ahead enough distance to be able to stop if something stationary appeared in the road. Suddenly I was overtaken by a cattle truck driving on the other side of the road, he must have been doing 40 judging by the speed he passed. Anything coming the other way would have been annihilated. I'm just lucky he must have seen my back light.
In that same link Prodigal gives us, check out the article by J. G. Ballard that immediately follows "A Kind of Madness". Written in the early seventies Ballard prophesises much of what has come about in the intervening years. From understanding the basic functions of the motor car/motorcycle, we have gone into the realms of dealer access only for many basic tasks so complex have engine management systems become. Hurrah for the side valve and a screwdriver for de-coking!