Blind Spots and Mirror Setup: How to Actually Eliminate Them
Most drivers set their side mirrors so they can see the back corners of their own car — which feels reassuring, but actually creates a large gap in coverage along both rear quarter panels that neither the side mirrors nor the rearview mirror can see. NHTSA has a specific, better method for setting them up.
Why the "traditional" mirror setup leaves a blind spot
With mirrors adjusted the conventional way, your rearview mirror and both side mirrors all overlap on roughly the same area directly behind your car. That overlap feels thorough, but it means the zones just beside your rear quarter panels — exactly where a car in the next lane tends to sit right before a lane change — aren't covered by any mirror at all. That gap is the blind spot.
NHTSA's method: turn the side mirrors out further than feels natural
NHTSA's Blindzone Glare Elimination method adjusts each side mirror outward by roughly 15 degrees from the traditional setting, so it picks up the adjacent lane's blind zone instead of duplicating what your rearview mirror already shows:
- Driver-side mirror: lean your head until it touches the driver's window, then adjust the mirror outward until you can just barely see the side of your own car from that head position.
- Passenger-side mirror: lean your head to the center of the vehicle (over the console), then adjust the same way.
- Rearview mirror: centered on the back window, framing the full width of what's behind you.
Once set this way, a vehicle passing through your old blind spot becomes visible in a side mirror right as it leaves the rearview mirror's field of view, instead of disappearing between the two.
This doesn't replace the shoulder check
Even with mirrors adjusted this way, NHTSA is explicit that small blind zones remain — just much smaller than with a traditional setup. Still turn your head and glance over your shoulder before changing lanes or merging. Properly set mirrors reduce how much you're relying on that shoulder check to catch something dangerous; they don't eliminate the need for it.
Sources
- National Highway Traffic Safety Administration, Blindzone Glare Elimination Mirror Method
- National Highway Traffic Safety Administration, Minimize Blind Spots Using Outside Mirrors
Always confirm current rules with your own state's official driver's manual.