Final answer:
Seeing red reflectors on lane lines facing you is a sign to slow down and prepare to stop, since it indicates you are driving the wrong way or facing oncoming traffic.
Step-by-step explanation:
When you see red reflectors on the lane lines facing you, you should slow down and prepare to stop. This is because the red reflectors indicate that you are on the wrong side of the road or are approaching a one-way roadway the wrong way. Reflectorized lane markers are designed to reflect headlights at night, thus when you see the red reflectors it means you are facing traffic head-on, which is a hazardous situation. To ensure safety and comply with traffic regulations, deceleration and readiness to come to a full stop are necessary actions.