Mirror, Indicate and Shoulder Check. Three words every driving instructor will use countless times a day. But what exactly is Mirror, Indicating and Shoulder Checking and what purpose does it serve?
Mirror, Indicate and Shoulder Check is the process a driver needs to complete before merging or changing lanes. As you can see for the image below the green highlighter area is the vision a driver would get from a mirror check. The reason for the shoulder check is to attain the red portion in the image known as the blind spot. A good way to think about it is that using your mirror will give you 90% of the information you need to make your decision and a shoulder check will provide you with the remaining 10% the mirror misses.