Funny Blonde Joke

A trucker stops at a red light and a blonde catches up to him. She knocks on the window and says, "Hi, my name is Heather and you are losing some of your load. "
The trucker just ignores her, the light changes, and he proceeds down the street. At the next light, the blonde again catches up and says, "Hi, my name is Heather, and you are losing some of your load. "
He ignores her again and continues down the street. At the next red light the blonde catches up, all out of breath, knocks on the window and says, "Hi, my name is Heather and you are losing some of your load. "
The trucker looks at her and finally he says, "Hi, my name is Kevin, it's snowing, and I'm driving a salt truck. "