I have personally found the daytime running lights to be more of a liability than a help. When driving on the empty desert roads i tend to drive on a lot, you do spend a lot of time passing slower cars, and are forced into the oncoming traffic lane. I have found that it is impossible to judge the distance of cars with these lights when they are approaching. For the same reason, I don't understand why people turn on their lights in areas which have a lot of passing going on... its very difficult to tell how far the little dots of light are from you. Ideally, you shouldnt pass if you can see a car there at all, but alas the world doesnt work that way.