I have always believed you should watch your mirrors at all times. In fact, watching them should be a top priority for any driver when it comes to safety. That way, you will know everything that is going on around you and can usually see when something is coming your way.
Glance at your mirrors regularly and note how fast everyone around you is driving. When you know how fast the vehicles around you are going, you can get a good idea of what is going to happen within the next several seconds. Watching them should be able to tell you who is going to be switching lanes, who will be speeding up or slowing down, who may be getting on or off the ramps, if someone is going to soon be right beside you, and if there is an escape route for you if something around you goes wrong. Being mindful of how fast everyone around you is going should help you predict most everything that will happen in your area within the next 5 to 10 seconds. It gives you an opportunity to plan ahead in case something happens around you that is drastic. I know a guy at who is a handyman in Alpharetta Ga who did have an accident years back, and is ultra cautious with this now.
Remember that drastic events don’t only happen in front of you. In my years of driving, I have occasionally had a vehicle that would spin beside me, and I have been able to avoid making contact with them every time because I was aware of what was going on and swerved enough for them to miss me. In those cases, if I had not been watching my mirrors closely, it is likely I would have been involved in a wreck that I had no part in originally.
When you are out on the road, things can happen in a split second. There is no room to make mistakes when you are driving an 80,000-pound vehicle either. Constantly watching your mirrors will help you better predict what the people around you are going to do so you can find your safe zones if there is an emergency. You are much more likely to get into a wreck if you do not regularly check your mirrors while driving.