If possible, you can take him to an area that you know has several common street signs (e.g., a stop sign, a railroad crossing sign, a “walk” or “don’t walk” sign) and have him stand by the sign, feel it, and watch what the cars do when they pass the sign. Then drive your car past the sign as well and ask your child to explain to you how you should react when you reach the sign. Repeat this over several days and weeks, and your child will become fluent in understanding traffic signs.