Using Your Mirrors

Guest article by Glyn Carson, Professional Driving Instructor

Glyn Carson

Some of you that are reading this are new to HDTs. They are a little different from driving a pick-up truck.

The mirrors are larger and need to be set differently than on a smaller truck.  Looking into either mirror you should be able see a narrow strip of your trailer.  About  ¼ to ½ inch on the inside edge of the mirror, you should be able to see the side of your trailer. The lines painted on the highway designating your lane should look straight alongside your trailer. You should also be able to see the marker light on the rear corner of your trailer.

How do you know where the back of the trailer is so you can change lanes? Follow this guideline. Park in a safe place and have someone stand at the rear of your trailer. You should be hooked and straight. Have your helper stand even with the rear of the trailer. Put a mark on the ground at this spot. Stay in the driver seat, in your normal driving position. Your helper should come to the mirrors and place a horizontal line on the mirror even with the mark they placed on the ground. The mark only needs to be an inch long on both sides of the mirrors. This will show you where the back of your rig is at all times. Any space above this mark and other objects in the mirror is the room you have between the back of your rig and that object.

The convex mirror is a very helpful mirror.  It should be set so the ground is visible at the rear truck axle and that the trailer wheels are visible as well. It should be turned to the outside as far as possible but continuing to see the edge of your truck and trailer. These mirrors will show you what is on either side of your rig and you will also use it when making turns. By looking in this mirror you will be able to watch your trailer wheels and make sure they miss running across a curb with any right-hand turn, and to keep you from driving over any cars when making a left-hand turn.

Caution: look up as well. Do not lose your mirrors or awnings because of a crown in the road or deep storm grate.  The more sloped the road the more your rig will lean to the right.  The top of your trailer can hit any object along a road.  This could be telephone poles, street signs or tree limbs.     The fender mirror:  This mirror lets you see the blind spot by your door.  I like my fender mirror beside the fender, most of them are now on top of the fender.  Either way, you want it to show the area from the front wheel to alongside the door. This will allow you to see the area next to your truck and it makes a good point of reference for the right fender in tight spaces.

About Glyn

Glyn has been a commercial driver since 1973 driving Limousines, Busses, and Semi-trucks. He has driven in forty-nine states and six provinces of Canada. He is certified by the state of Ohio to teach Class-A CDL and since 2013 has been teaching RVer’s to drive their rigs safely.

Glyn has participated in Bus Driving Rodeo’s and has several safe driving awards.

While he was working in Alaska, he drove on the ice road, on the frozen ocean and also worked for the State Highway Department plowing the snow off the ice road so the truckers could safely go to the North Slope oil fields.

Glyn can be reached by email at: