Traffic lights are important for safety on roads. They help cars, buses, and bicycles move safely. Most traffic lights have three colors: red, yellow, and green. Red means stop. Cars must stop and wait. Yellow means be careful. Drivers should slow down. Green means go. Cars can go straight or turn. Sometimes, traffic lights have arrows. These arrows show drivers when they can turn left or right. Pedestrians, people who walk, also use traffic lights. They use a special light that shows a person walking or a hand. A walking person means it is safe to cross the road. A hand means do not cross the road. Traffic lights make roads safer for everyone.