No need for derech eretz. Without scaring your child, let him know that he need not be polite to people if he feels threatened. Sometimes, we teach our child to be so obedient, that they do not stick up for themselves if they are imperiled. Let your child know that there are occasions when it is okay to scream, “No!”
Indicate “safe” adults: Just as there are safe spots while walking home, teach your child about safe people on the street. While your child should avoid speaking to strangers, there are some extenuating circumstances when speaking to strangers is necessary. Explain that he should look for a woman with children or a police officer if he is in need of assistance. Understanding that there are adults he may speak to will not only make life less scary, but will also give him the skills to select wisely if he must ask a question of a stranger.
As parents, we often think about teaching our children the ABCs, but we don’t always realize how important it is to teach them how to function in their “real” world as well. With a little help, your child can learn what to do when “the sidewalk ends” and gain the essential skill of street smarts.