Loading Cargo & Roof Racks

Loose or poorly secured cargo kills and injures people on the road. Items that fall off vehicles cause crashes, and unsecured items inside a car become flying objects in a sudden stop. Whether you’re hauling lumber, a ladder, luggage or a mattress, the rule is the same: know your limits, balance the load, and tie it down so it can’t move.

• Drivers
• Families
• Home Projects

Know your vehicle’s limits

• Payload capacity: the maximum weight of passengers and cargo your vehicle can carry. It is on the door-jamb sticker and in the owner’s manual. Passengers count.
• GVWR and axle ratings: don’t exceed the gross vehicle weight rating or axle ratings. Overloading hurts steering, braking, tires and suspension.
• Roof rack and roof limits: the roof has a maximum load that is often much lower than people expect. Many vehicles are rated at around 100 to 165 pounds, including the rack and carriers, and the limit is lower while driving than while parked. Check the owner’s manual and the rack maker’s instructions, and follow whichever is lower.
• Trailer hitch limits: the hitch, receiver and cargo carrier have their own ratings. See Towing Trailers.
• A loaded vehicle handles differently: it takes longer to stop, leans in turns and is affected more by wind. Heavy roof loads raise the center of gravity and the rollover risk. See Safe Driving Basics.

Loading inside the vehicle

• Put heavy items low and forward, as close to the center of the vehicle as possible, and light items on top. Don’t stack cargo higher than the seat backs.
• Secure loose items. In a sudden stop, an unsecured object keeps moving at the vehicle’s speed. A laptop or a toolbox can hit someone with deadly force. Use cargo nets, straps, a cargo barrier or tie-down points, and keep items behind the rear seats, not on the seats or the rear shelf.
• Keep the driver’s area clear. Don’t let items roll under pedals or block mirrors and windows.
• Use seat belts for passengers, and don’t let anyone ride in a cargo area, including pickup beds. See Seat Belts & Airbags.
• Never carry a loaded gas can, propane cylinder or other fuel inside the passenger compartment. Carry approved containers upright, secured, in a ventilated area such as the truck bed on the ground rules and away from heat. See Fuel Storage Tanks on Jobsites and Propane.
• Pets and children need their own restraints. See Traveling with Pets and Child Car Seats.

Roof racks and carriers

• Use a rack made for your vehicle, and install it as the instructions say, with all bolts and clamps tight. Check them after the first few miles and regularly.
• Choose the right carrier: cargo boxes keep items dry and are more aerodynamic. Open baskets and cross bars need straps and nets. Ski, bike and kayak carriers are made for their loads.
• Spread the weight evenly across the crossbars, with the heaviest items in the middle, and keep the load within the rack’s and the roof’s limits.
• Watch your height. Roof loads add to your vehicle’s height. Garage entrances, drive-through awnings, bridges and trees have taken off many roof boxes. Note the height on a card on the dashboard.
• Expect more wind noise, drag and fuel use, and slower acceleration and longer stops.
• Remove racks and carriers when you’re not using them.

Tying down loads

• Use proper tie-downs, such as ratchet straps, cam buckle straps or rope with the right knots, rated for the weight. Don’t use bungee cords for heavy loads, and don’t depend on friction or on a tarp alone.
• Use at least two tie-downs and secure every piece. Tie to solid anchor points on the vehicle, not trim or plastic.
• Tie down in both directions: prevent forward, backward, side and upward movement. Run straps over the load and underneath, crossing where needed.
• Pad sharp corners so straps don’t cut. Don’t overtighten loads that can be crushed.
• Keep straps short and tidy. Tie off loose ends so they don’t flap in the wind and damage paint or get caught in a wheel. Twist long straps to reduce humming.
• Cover loose loads, such as soil, leaves, rubbish and light materials, with a securely tied tarp or net. Many states fine drivers for littering and unsecured loads.
• Do the shake test: push and pull on the load. If it moves, tighten or re-tie it.
• See Cargo Securement and Tarping for how professional drivers do it.

Long loads and overhangs

• Ladders, lumber, pipe and plywood: carry on the roof rack or in the bed with the front tied down firmly, and the back secured. Check that nothing slides forward through the windshield in a stop. See Ladder Safety at Home.
• Overhang rules: states limit how far a load can stick out the back or sides. When a load extends beyond a set distance, often 4 feet or more at the rear, you must mark it with a red flag (commonly about 12 to 18 inches square) by day, and a red light at night. Rules vary, so check your state’s law.
• Don’t block your view through the mirrors and windows, or cover the lights and license plate.
• Drive more slowly, take turns carefully and avoid sudden maneuvers. Lumber can whip in the wind.
• If the load is bigger than a vehicle can safely handle, have it delivered or rent a truck.

Hitch carriers and truck beds

• Hitch cargo carriers and bike racks add weight behind the rear axle, which reduces front-wheel traction. Stay under the hitch’s rating, and make sure lights and plates are visible.
• Pickup beds: tie items down to the bed anchors, not just by the tailgate. Heavy items should sit against the front of the bed. Don’t carry things on a tailgate that can’t withstand the load.
• Never let people or pets ride in a pickup bed.

Check the load

• Look at your load before you drive, after the first few miles, and at every stop. Straps stretch and loads settle.
• Check straps, tarps and anchors in rain and wind, and after hitting a bump or hard braking.
• If something falls, don’t stop in a traffic lane to pick it up. Pull over safely, or report it to the authorities. See Breakdowns.

Loading checklist

• Load is within payload, axle and roof limits
• Heavy items low and centered; nothing loose inside the cabin
• Rack is installed correctly and checked; height of the load is known
• Ratchet or cam straps used, in two or more places, and the shake test passed
• Overhangs are flagged and lights and plates are visible
• Fuel and propane are never inside the passenger area; load rechecked at stops

Last updated: October 4, 2026