It's common to see all manner of things loaded on the rooftop of vehicles during the summer months, from bikes to kayaks to boats. Kiwis love to explore their own backyard - love to attach all manner of things to the outside of vehicles.
There are rooftop boxes, roof racks for sports equipment, bike racks for use with and without tow bar, camping awnings and tents, or you can completely think outside the box... and carry a small boat.
At a time where we’re only able to embark on "staycations", this summer we’re bound to see an abundance of cars packed to the brim on our roads. With this in mind, we’ve put together some information to help you load your car safely.
How much weight can your vehicle carry?
Each vehicle has a manufacturer-specified maximum safe laden (or loaded) weight, also referred to as gross vehicle mass/weight (GVM/GVW). Overloading the vehicle beyond this weight can compromise the vehicle’s body, brakes, chassis, wheels and engine, not to mention the impact on fuel economy.
The maximum safe laden weight (minus the unladen weight) gives you the payload or maximum load (including objects, people and animals) that the vehicle can carry. If you are unsure, contact the manufacturer of your vehicle (for some used-imported vehicles this may be hard to obtain).
Safe and Secure
All loads should be properly restrained so they can’t shift around while the vehicle is moving. This can be achieved by ensuring the load is:
- Securely packed inside compartments that are rigidly attached to the vehicle.
- Held securely in racks or cradles or frames designed to fit that size of object and which are rigidly attached to the vehicle.
- Held by lashings (webbing straps, ropes, chains) or clamps securely attached to appropriate anchorage points (rails, hooks or eyes).
When you secure a load, bear in mind that it will try to move: forwards when you brake, sideways when you turn, backwards when you accelerate, and upwards when you go over bumps.
Loads inside vehicles
Objects inside a vehicle should be restrained against movement, as they can easily turn into missiles in the event of an accident or sudden braking. The back of car seats (especially folding seats) may not be strong enough to restrain a load placed behind them. So you may need to use straps attached to appropriate anchorage points fitted within the vehicle.
Other options include adding a load retaining wall or beam, or a full or partial cargo barrier.
Never rely on the grip of the floor of the vehicle to restrain a load. Many objects are smooth and can slide easily across most surfaces. Also remember that this grip can be lost when the vehicle goes over a bump.
Loads on roof racks
Before you buy a roof rack, check your vehicle’s manual (or ask the manufacturer) to find out exactly how much weight your vehicle can safely carry on its roof. Check to see that the roof rack can carry the intended load, and make sure you purchase a rack that suits your vehicle’s roof shape and can be attached to the appropriate places on your vehicle.
Small Boats
Ideally, boats should be carried on trailers that have been specially designed to contain their size and shape. For information on towing a boat, the AA has towing weight information. If any part of the boat is not contained, it needs to be appropriately restrained to prevent movement.
Spreading the load on a roof rack
Evenly distribute objects along and across the rack (between the left and right sides, and between the front and back of the vehicle) and always be careful carrying any long or bulky objects. Remember that the maximum rear overhang is 4 metres for a ridged vehicle from the rear axle and 1 metre from the rear of the vehicle. More information can be obtained from the NZTA.
Both the straps holding the objects onto the rack and the fittings that hold the rack to the vehicle should be strong enough to keep the rack and the objects secure in strong crosswinds. If you’re unsure, use additional lashings and attach these directly to the vehicle.
Remember that:
- The more weight that you carry on the roof of your vehicle, the less weight you will be able to carry inside your vehicle.
- Roof racks increase wind resistance and buffeting.
- You may need to travel slower than usual, and your vehicle may require more fuel.
Recreational equipment
Bikes, surf boards, paddles, kayaks, canoes, snow boards, skis and similar items should be carried on racks that are suitable for the weight and size of the object. At least two clamps or lashings need to be used to keep them secure during travel if they’re carried outside the vehicle.
Large boards that are placed on a roof rack can be severely affected by the air flowing over the vehicle. Both the lashings (or clamps) holding the board to the rack, and the fittings holding the rack to the vehicle, need to be strong enough to hold the board in place throughout the journey. Use additional lashings connecting the load directly to the vehicle if you’re carrying a large board or canoe.
Be mindful that bicycles carried on tow-bar-mounted cycle racks can sometimes cover up the number plate or essential lights on the back of the vehicle. In these circumstances the driver is legally obliged to fit additional lights and/or number plates on the back of the load. A vehicle lighting retailer or garage can advise you on purchasing and fitting temporary lights to your load.
With the recent increase in popularity of e-bikes, it’s worth noting that they can weigh significantly heavier than regular bikes, so take this into consideration when loading your car.