When you drive, it is essential to pay attention and be alert. You must be ready for anything that may come into your path or any conditions that may change and require you to react.
If you have inattentional blindness, Simply Psychology explains it means you do not see something clearly in front of you.
With inattentional blindness, you should see something, but you do not because you are not focused on whatever it is. Your attention may have been on something in the distance, like a stop light, so you were not paying attention to what was happening right in front of your vehicle. This type of situation is what can lead to rear-end accidents.
The key to this is that something is in front of you and should be easy and clear to see, but you fail to see it. Inattentional blindness does not happen if there is something in the way to obscure your line of sight.
Inattentional blindness is a side effect of distracted driving. Even though it happens when you are watching the road and is not due to taking your eyes off what is in front of you, it is still due to distractions. The distractions are just cognition. Perhaps you are thinking about something else besides driving, or you allow yourself to focus on something else on the road instead of properly scanning the whole road in front of you.
Knowing how inattentional blindness happens can help you to avoid it. Basically, the key here is that if you focus on driving and pay attention to the task at hand, then you can generally avoid missing things clearly in your path as you drive.