Safe driving takes concentration, and that is all the more true if you’re driving a heavy truck and pulling a trailer — be it an enclosed equipment hauler or a flatbed carrying an excavator or any other work equipment. Here are some safety tips to keep in mind when choosing, loading and maintaining trailers. For more complete information, consult your trailer’s manufacturer or your state or local highway safety agency.

Load carefully. Measure your hauling objects’ length, width and height to be certain they will fit on the selected trailer. Some users will place or line up the objects on the ground to take measurements before actually placing them on board. Know the weight of what you plan to haul. That will help you decide whether the frame size, frame strength, axle capacity and ramping options of the trailer you have chosen will suit your needs.

Consider the two vehicles. Make sure the weight allowed for the tow vehicle matches (or is less than) gross vehicle weight rating (GVWR) of the trailer. Your owner’s manual will list your vehicle’s GVWR. If you can’t find the manual, contact your vehicle dealer or the manufacturer.

Take care of the tires. The tow vehicle tires must be inflated to the proper pressure. Underinflated tires will wear faster and could cause the trailer to sway. Keep tire pressure on the high side of the tires’ recommended range, since a fully inflated tire carries more weight and runs cooler than a tire that is low on air. Don’t forget the trailer tires — check their pressure, too. You’ll find pressure ratings on the tire sidewalls.

Check the coupler. Look for fatigue, damage, cracks or missing parts before towing. Test the lock mechanism to make sure it latches correctly and completely. Use a hitch ball that matches the coupler size for the trailer. Also check trailer lug nuts often and when necessary tighten them to the proper torque.

Keep it level. When the trailer is hooked to your vehicle, make sure both are level. If the vehicle carries too much tongue weight, it will not ride level and may not steer properly. Tongue weight should be 10 to 15 percent of the weight of the trailer and contents.

Maintain breakaway systems. Electric-brake trailers have a breakaway kit (battery, battery box, and break-away switch with attached plunger and cable). If your coupler separates from the tow ball, the breakaway system will supply power to the brakes and bring the trailer to a stop. The breakaway kit battery should be charged periodically. If the wet cell battery has an inadequate charge, it can freeze in winter and is then useless. You should attach the breakaway switch cable to its own anchor to provide the correct amount of play—neither too loose nor too tight.

Watch the wiring. The wiring that powers your trailer can wear out and fail, especially if you drive gravel roads, which can cause the wiring to be bombarded with abrasives. Inspect wiring regularly and make sure it is clean and tucked up into a protected position. It helps to wash the underneath now and then with a pressure washer to remove corrosive salts. The electrical system also can fail through poor contacts in electrical plugs. A spray of the plugs with penetrating fluid or WD-40 will help break up corrosion.

Inspect the suspension. Your trailer suspension may contain hangers, leaf springs, shackle straps, shackle bolts, equalizers, u-bolts, axle plates and other parts. Inspect and replace them as needed as part of normal maintenance. Severe suspension wear may cause the trailer to wander, creating serious instability.

Check wheel bearings. The bearings on a trailer are critical maintenance items. Wheel bearings need the correct amount of grease, and tapered wheel bearings should have the correct adjustment.

There’s more you need to know—consult your trailer or towing vehicle manufacturer. Still, these tips will get you started on the way to safe towing of equipment to your work sites.