As Ethel said, common sense is the main thing, though it is often lacking in modern drivers! Obviously if you are in a car coming uphill and a truck, bus or tractor is coming down, its a lot easier for the car to reverse. However, not all of them do when I'm in my truck and they expect me to get out of the way. I'm not being sexist, but women in 4x4's on the school run are worst for this. I don't think they know that the car can go on the verge a bit. I find getting the paper out and pouring a cup of tea normally gets the message across!