Blind Spot Driving Rules: How to Adjust Mirrors to Completely Eliminate Blind Spots

The Anatomy of a Vehicle Blind Spot: The Dangerous B-Pillars

Every year in the United States, over 840,000 side-impact and sideswipe collisions occur during routine lane changes, resulting in more than 300 fatalities, according to data from the National Highway Traffic Safety Administration (NHTSA).

The vast majority of these crashes stem from blind spots: triangular areas flanking both sides of the vehicle where adjacent passenger cars, motorcycles, and cyclists are completely hidden from standard mirror views behind the car’s roof pillars (B-pillars and C-pillars).

The Traditional Flawed Mirror Setup (Why Seeing Your Own Car Fails)

Most drivers adjust their mirrors incorrectly because they were taught the outdated "rear fender" method:

• The Mistake: Sitting upright and adjusting both side mirrors until the rear flanks of your own car occupy the inner 30% of the mirror glass.
• Why It Fails: Your car's body panels never move; they do not need to be monitored. Angling side mirrors inward merely duplicates the view already provided by your center rearview mirror, while leaving the critical 45-degree blind zone alongside your rear doors completely invisible.

The SAE "Blindzone & Glare Elimination" (BGE) Setup (Step-by-Step)

Published by automotive engineer George Platzer in SAE Technical Paper 950601 and endorsed by the American Automobile Association (AAA), the BGE (Blindzone & Glare Elimination) method angles mirrors outward to create a seamless panoramic field of view:

Frame the Entire Rear Window in the Center Mirror

Sit in your normal driving posture as practiced in your pre-drive inspection. Adjust the center rearview mirror so that it squares and frames the entire back window glass. The center mirror is your dedicated tool for viewing traffic directly behind your bumper.

The Driver-Side "Glass Lean" Technique

Lean your head to the left until your temple gently touches the driver’s side window glass. From this tilted position, adjust the left side mirror so that the rear edge of your vehicle’s body is just barely visible in the inside edge of the mirror glass. When you return your head to normal upright center, you will no longer see your own car, but will instead view the active traffic lane directly in your blind spot.

The Center Console Lean for the Passenger Mirror

Lean your head to the right so your head is positioned directly over the center console (between the driver and front passenger seats). From this position, adjust the right side mirror so the rear right edge of your vehicle is just barely visible. Return to normal upright posture.

The Seamless Panoramic "Hand-Off" Visual Test

When configured correctly, passing vehicles experience a flawless visual hand-off:

• Far Behind: A trailing car appears centered in your inside rearview mirror.
• Approaching: As they pull out to pass you, their front bumper glides into your side mirror before their car leaves your center rearview mirror.
• Alongside: As they pull alongside your door, their vehicle appears in your peripheral vision before their bumper leaves your side mirror.

Why Examiners Still Require Over-the-Shoulder Head Checks

While the SAE mirror setup drastically reduces highway sideswipes, it does not replace the physical head check on the DMV road test.

During your behind-the-wheel exam, performing the full S.M.O.G. procedure (Signal, Mirror, Over-the-shoulder, Go) is mandatory. Failing to physically turn your chin to your shoulder to verify blind spots before merging or changing lanes is scored as an Automatic Failure for "Unsafe Lane Change" under DMV road test rubrics.

Interactive Knowledge Check