I think the key word in your question is correcting. Coercion and punishment might work in some cases, but it strains your relationship and deteriorates trust. The best thing to do is take the child aside and get him/her to explain their actions. Ask them if they think what they did was wrong. Explain to them why what they did was wrong, and what negative consequences come from that sort of behavior. Make sure you do this as calmly as possible. Staying calm puts you in control of the situation far more than blowing your top does. Be the rational adult. Also suggest a better way the child could handle the situation in the future.
Of course, if the kid runs into the street and almost gets hit by a car, an emotional reaction will probably be unavoidable and also helpful. In that case your emotions will indicate to the child how serious the situation is.