How to Safely Make Mirror Adjustments

Trucks cause a significant number of deaths and injuries in backing accidents, with the National Safety Council (NSC) estimating 500 deaths and 15,000 injuries annually from general backing accidents. While specific data on only truck backing incidents is limited, large commercial vehicles are more prone to these accidents due to larger blind spots and difficulty maneuvering.

Backing accidents are common in parking lots and private properties and are often caused by a driver's lack of awareness of their path, failure to check blind spots, and difficulty seeing pedestrians or smaller vehicles.

To properly adjust truck mirrors, sit in your normal driving position, and set the driver's side mirror so the rear corner of your trailer is barely visible in the inside edge of the mirror, with the horizon about 1/3 of the way up.

The passenger's side mirror should be angled even further out, showing only a sliver of the trailer's rear corner, to provide the widest possible view of the lane beside the truck. Adjust both mirrors vertically so you can see a good amount of the road and the horizon without seeing too much of the sky.

To properly adjust truck mirrors, sit in your normal driving position, and set the driver's side mirror so the rear corner of your trailer is barely visible in the inside edge of the mirror, with the horizon about 1/3 of the way up.

The passenger's side mirror should be angled even further out, showing only a sliver of the trailer's rear corner, to provide the widest possible view of the lane beside the truck. Adjust both mirrors vertically so you can see a good amount of the road and the horizon without seeing too much of the sky.

Driver's Side Mirror

1. Adjust Vertically:

Tilt the mirror so that about one-third of the mirror shows the horizon, and the remaining two-thirds show the road.

1. Adjust Horizontally:

Angle the mirror outward until you can just barely see the rear corner of your truck or trailer in the inside edge of the mirror.

1. Check for Blind Spots:

Shift your head slightly to see if you've eliminated the blind spot right next to your truck.

Passenger's Side Mirror

1. Adjust Vertically:

Position the mirror so the horizon is visible, similar to the driver's side.

1. Adjust Horizontally:

Angle the mirror outward even more than the driver's side mirror to show the widest possible view of the lane beside the truck. You should see only a tiny sliver of the truck's rear corner.

Tips for Maximum Visibility

• Maintain Clean Mirrors: Keep your mirrors clean to ensure a clear, obstruction-free view.
• Adjust for Load Changes: Slightly adjust your mirrors after loading or under different weather conditions to maintain maximum visibility, according to Start CDL Training.
  
• Use Convex Mirrors (if equipped): If your truck has convex mirrors, ensure they reveal the blind spots that the standard mirrors don't cover, giving you a broader view.

When backing, be certain to always sweep with your eyes checking both the driver's side mirror and passenger side mirror. As you scan across remember to check out your windshield for any possible obstructions as you turn your vehicle.

Many drivers develop bad habits where, just before backing the vehicle, they scan both mirrors to see that the way is clear. As they begin to back, they do so by only using the driver's side view, never taking their eyes off to check out the windshield or the passenger side. Remember much can change around a vehicle in a short period of time. Pay attention to the front and both sides.

Photo by Sander Yigin on Unsplash