Towing rules

Taking the garden rubbish to the tip? Moving the kids into a flat? Carting the boat to the beach? Make sure you're up to date with towing rules.

Responsibility

The driver of the car towing a trailer (not another driver, and not the owner of the trailer) is responsible for any damage that happens while towing. If the trailer has a safety problem, such as an expired WOF, the driver of the towing car is responsible.

WOF

Trailers must have a current WOF and registration.

Speed

The open road speed limit for light vehicles towing trailers is 90km/h. The NZ Police will apply a 5km/h tolerance to towing speed limits, in all speed zones. This means if you travel 56km/h in a 50km/h zone, you can expect to get a ticket if caught.

Wheels

Trailer tyres now come under the same scrutiny as car tyres. They must have legal tread and be the same type and size on each axle. Wheel bearings are now also checked.

Tow ball

There are two sizes: the old inch and 7/8ths ball (47.5mm) and the newer 50mm ball. Be careful with using a smaller ball in a larger coupling, as they can come apart. Some couplings are designed to cope with both ball sizes. If your car has a 50mm tow ball, you won't be able to get it into a smaller coupling.

Coupling

The trailer must have a secure coupling, which should include a double-locking mechanism, or a locking pin. When hiring a trailer, ask the hirer to demonstrate the coupling works correctly.

Safety chain

The trailer must have an adequate safety chain, permanently attached to the trailer. The LTSA prefers it to be bolted on. A shackle can be used only on the chain-to-towing-vehicle connection. Welding the chain onto the trailer is acceptable if done properly. There are additional requirements for trailers over 2000kg.

Lights

Trailers must have at least one working tail light (if first registered after 1 January 1978). Hire centres should supply suitable connectors, but your car also needs a correctly wired socket.

A trailer doesn't need indicators and brake lights provided the lights on the towing vehicle are visible to drivers behind you, or you can make visible arm signals out the window. If you do a lot of towing it's best to have indicators and brake lights fitted. All lights on a trailer must work correctly.

Brakes

Trailer brakes aren't required unless the loaded weight is over 2000kg. Even without separate brakes, both car and trailer must be able to stop from 30km/h in less than seven metres. Over 2000kg, different rules apply.

Weight

Maximum load weight depends on the car and trailer. Some cars can tow less than 500kg. Check your car's handbook.

A typical trailer load of builders' mix is around 900kg - and a typical trailer will add another 200kg or so. It all stacks up.

Exceeding the limit may invalidate the warranty on a new car if you later have a problem with your gearbox or brakes.

If you have a really big rig, like a heavy 4WD and an eight metre long caravan, you could exceed the allowed gross vehicle mass for a car licence. This is 4500kg, including both vehicles, passengers, luggage, and so on. You need a class 2 (truck licence) to drive any combination that exceeds 4500kg. A typical six cylinder car, plus a six metre caravan and load, should be comfortably below the limit.

Load security

The load must be secure. If necessary, use a net or tarpaulin in addition to ropes.

The load can overhang the rear by up to four metres - measured from the axle. If it overhangs by more than one metre, it must be flagged. At night red lights must be fitted to the rear. In daylight you should attach a fluorescent flag (white, red, orange or yellow), sized 400 x 300mm.

A load can extend sideways up to 1.25 metres from the centre line of the trailer, but must be flagged if it extends more than 200mm beyond the sides.

At night, you need to mark an extended load with white or amber lights to the front, red to the rear.

Load distribution

Stack your trailer so around 10 percent of the total weight pushes down on the tow ball. Put the heaviest items slightly forward of the axle, to reduce the tendency to sway.

Dimensions

You can tow a trailer that's up to 2.5m wide, 4.25m high when loaded, and 11.5m long, as long as the combined car and trailer length does not exceed 20 metres.

Insurance

Not all car insurance policies cover a trailer while it's being towed. Check your policy.

Hiring a trailer

Trailer hire is covered by the Consumer Guarantees Act. This means the trailer should be fit for its purpose, and should meet all safety requirements.

Make sure it is safe before you drive it away. Check the lights, tyres and so on, as listed above. Couple up the trailer and then pull up on the coupling (or bounce up and down on the rear of the trailer). Does the coupling hold securely?