When the rabid racer whizzes by, don't think he's an idiot, instead think he's just learned a loved one is in the emergency room. He's got to get there as quickly as possible. Of course you don't know if this is true, but it doesn't matter. If you can believe it, it immediately relieves your anger. You can even add a prayer for the person in the ER, if you like.
As for the lame driver blocking your way, just take a breath and think: "This person is a bodhisattva; he's protecting me from driving too fast; he's making me aware of my own impatience; he's my teacher." Naturally, the other half of this practice is to stop tailgating this slow-driver and just pass naturally, thankful for the moment.
— Taigen Daniel Leighton in Just Add Buddha! by Franz Metcalf