How Commercial Truck Mirrors Help Prevent Collisions

Commercial trucks don’t have rear windows or interior rearview mirrors to help the driver manuever the vehicle. This means that the truck’s side mirrors are an essential tool for the driver to visualize their surroundings. These mirrors prevent collisions by minimizing large blind spots and guiding blind backup movements. Today’s commercial truck mirrors even help track traffic speeds. When used in combination with defensive scanning techniques, these mirrors keep both the truck’s driver and smaller passenger vehicles safe.

Shrinking Blind Spots and Monitoring Traffic Flow

Commercial trucks have four main blind spots. It’s very hard for the driver to see directly in front of the vehicle. They also can’t see directly behind them, and it’s extremely hard to see what’s immediately along each side of the truck. This is why properly placed mirrors are so important.

Trucks rely on a combination of mirror types to see their surroundings and reduce visibility gaps. Flat side mirrors are essential on all trucks. These provide the driver with a clear and accurate view of the adjacent lanes farther down the road. You’ll also see trucks with convex “spot” mirrors. Spot mirrors are curved and provide one with a wide-angle view closer to the trailer. This reveals to the driver any small vehicles traveling within inches of the truck.

Hood and fender mirrors further enlarge the driver’s view. These are placed on the front corners of a truck. They provide the driver with a way to see down the immediate side of their cab. This helps protect pedestrians and cyclists sharing city roads with large trucks.

Specialized mirrors are capable of monitoring traffic flow and speed by providing real-time tracking data. This allows drivers to evaluate how fast traffic is moving by looking in their side mirrors. They can then more readily predict the action of aggressive drivers, and it helps them safely match the flow of traffic. Furthermore, they are able to ensure that they have enough time and space to react before initiating lane changes or braking.

Safe Lane Changes

Changing lanes is quite challenging for truck drivers because of the extreme length of their semi-trailers. Determining when a truck has completely cleared a vehicle in an adjacent lane requires the ability to see specific visual benchmarks in its mirrors.

When passing a smaller vehicle, truck drivers use what they call “the headlight rule.” The driver won’t initiate a lane change until they can clearly see the entire front hood and both headlights of the vehicle they’re passing in their flat side mirrors. If the driver can only see a portion of that vehicle they’re passing, such as a window or side door, they know it’s still too dangerous to make the lane change. Also, if that small vehicle looks large in the mirror, they know it’s too dangerously close to the trailer. The vehicle must be fully apparent in the mirror and look small in size before changing lanes is considered safe.

Blind-Side Backing

Blind-side backing is when a driver is reversing the truck, but the trailer is blocking their direct line of sight when looking over the passenger side. This is when the convex mirrors come into play. Drivers rely heavily on these wide-angle spot mirrors mounted below the flat mirror. The convex lens captures a wider view of the trailer’s side and the truck’s rear corner. It acts as a window to the blind side. When backing up, the driver will pick a specific reference point. This could be a line, a marker, or a cone. They use the spot mirror to steer the trailer towards this reference point. The driver needs to steer the tractor to the left, away from the reference point. This pushes the tail of the trailer to the right. The driver then counter steers to bring the tractor and trailer back into alignment. This is all done as they back into their preferred space.

You’ll often see drivers lean out of their window or open the door slightly to get a direct line of sight beyond the side of the truck when the mirrors are limited. Moving backward at an extremely slow pace allows the driver to catch small misalignments before they become a major issue. If they lose visibility or the angle of the truck becomes uncertain, the driver needs to stop, set their brakes, and physically walk back and check the space.

Mirrors alone can only do so much. The driver needs to adjust their seat in an upright position before touching them. While parked on level ground with the truck and trailer straight, they can adjust the flat mirrors. The goal is a 90/10 view. This means that 10% of the mirror needs to show the edge of the trailer. The other 90% will show the adjacent lane of traffic. To adjust the convex mirrors, they need to be tilted to cover the immediate blind spots right next to the truck doors and the lower side of the rig. Hood or fender mirrors should be angled to show the dangerous blind spots in front of the front bumper and cab. Most importantly, mirrors need to be cleaned frequently. The driver should be wiping them down before each trip with a glass cleaner. They should also check the stability of the mirrors by touching and verifying that the brackets are tight. Truck vibrations can loosen these, so adjustments will be necessary as needed. With a little care accidents can be avoided, but if not, an experienced truck accident lawyer like those at Curcio Law can help after a crash.