there is a car coming

How many of you have been out driving and have seen this sign? I am going to go out on a limb and say that this sign is useless. According to the logic of the sign, if we don't see a sign that says "pass with care" we can pass with reckless abandon. I guess I should only worry about my life and those around me when I see this sign and feel the need to pass the car in front of me.