New Zealand has strict driving laws & protocols that everyone is expected to adhere to. Like the British, the Kiwis drive on the right-hand-side of the road & if you hire a car or campervan, the steering is also on the right. If you are coming from a country where you have driven on the left, this can be slightly disorienting, but with some simple precautions, it is easily mastered. Before you arrive, read the New Zealand Road Code. Do this even, or perhaps especially if you intend to bicycle. While most things are common across the world, pay careful attention to some things.
Speed limits are in Km not miles, and are generally not high, mainly because there are very few multi-lane highways. The main roads that traverse New Zealand are either single or dual lane carriageways. And the police are quite strict in enforcing the limits. New Zealand has speed cameras on most main roads & there are also mobile speed units that are placed in random locations. In addition, all police cars are equipped with speed sensing radar to check the speed of oncoming traffic. 100Kmp/h is the maximum speed on highways and the limit in built up areas is 50Kmp/h. Most open roads also have extremely useful indications of speed at corners. Intersections are the most dangerous areas on the roads, so ensure you are familiar with the give way rules, especially on smaller country roads that sometimes have minimal signage. If you do see a stop sign, then stop before doing anything else. Don't just slow down & keep driving. This NZ Transport Agency video is essential viewing.
Most roads in New Zealand are sealed, but in the more remote areas, gravel roads are more common, known as 'metal roads'. If you intend going off the beaten path a great deal, you would be best hiring a 4wd vehicle. This also applies if you are heading into the ski fields or driving remotely in winter. Most roads are kept open in winter, but occasionally after especially major snow falls roads have to be closed. Signs are placed well in advance of the closed section, but options can be limited in areas where there are only one or two roads. You will need to carry, and know how to fit, snow chains. There will be signs if they are required on major roads, but you may need to use your own judgement on smaller roads. Fit them to the driven wheels (on all four on 4wd vehicles) & drive slowly, never braking hard, always softly pumping the brakes when required. Make sure all the basic things like heaters, defrosters & lights are working before you set out & remember to carry a mobile phone, warm clothes, rugs, water & an ice scraper!
If you are hiring & come from a country that drives on the left, consider hiring an automatic vehicle as this may allow you to concentrate more on the roads & less on the fact that the gears are in a strange position. Should you be unfortunate enough to have any problems, the key number you need to know is 111, which is emergency services. (To report traffic incidents from your mobile, dial *555.) If you are in an accident, make sure you get the other driver's name, licence number, insurance details, the vehicle's plate number & VIN (vehicle identification number from the lower corner of the windshield) & contact your rental company or their approved repairers. If you need to organise things yourself, the website towing.com is a good place to start. If anyone is injured, you must report the incident to the police.
Navigation in a strange country can also be challenging. Always study maps & routes before setting off & ideally use something like Google Maps to talk you through your planned route, which you will find useful as most places in New Zealand have mobile coverage. If you are selecting an overseas roaming partner for your mobile network, Spark (the original national carrier) has the widest mobile network in the most remote places, whereas they are equal with most other carriers in more densely populated areas. It is worth considering buying a local SIM card for your mobile phone - these are available at the airport when you arrive or from any telecommunications retail outlet. The NZ Transport Agency has an excellent site detailing all the road & traffic conditions & you can even see live snapshots from traffic cameras in strategic busy places. On this site you can plan your trip & see any potential issues before you start. You can also monitor the latest weather on the official metservice website, although weather in New Zealand can be very changeable. The rain radars are extremely useful to track rainfall & it is entirely possible to watch the rain skirting past you a few kilometres away!
As a visitor, if you have a full driving license from your country, you can drive on that for up to 12 months, after which you will need to convert it to a New Zealand one. If you leave the country before 12 months & then return, the clock starts again. Your full license allows you to drive broadly the same class of vehicle in NZ as you are able to at home. If your license is not in English, you will need to obtain an English translation before you are allowed to drive. This can be obtained from your embassy or consulate or your home country's licence issuing authority or an NZ Transport Agency authorised translation service. It may be easier simply to apply for an International Driving Permit in your home country, as this is also acceptable in NZ, but as a translation - carry your full licence as well. The same rules apply to motorcycles. If you have a full motorcycle license you can ride any bike. You must carry your licence with you at all times. If you are stopped and cannot produce your licence, you may be treated as if you have no licence at all.
If you have a learner or provisional licence, then restrictions will apply & you will probably find it impossible to rent any vehicle, as rental car operators demand full licences. They also demand credit cards as a means of payment and deposit, so you will not be able to rent without a credit card. You have to be over 18 (21 with some companies) to rent a vehicle in New Zealand, although some will still charge a young person's fee if you are under 25. It pays to shop around. You can normally rent a car on the North or South Island & take it across the Cook Strait on the Ferry (with InterIslander or BlueBridge) to the other island (but do check), but most agreements require you to return the vehicle to the same place. You can hire a car in one location & return it to another but you have to arrange that specifically & there will usually be a return surcharge. Rental companies bar you from driving their vehicles on any beaches, stream beds or paddocks, even if they are 4wd vehicles, and they usually don't allow you to tow anything. You can generally drive on 'metal' (gravel) roads, but there is always a list of specifically excluded roads - do check. Check that your rental company uses a breakdown organisation to help you if you have any mechanical issues (usually AA Roadside Assistance). Most companies can rent you child safety seats with your car, but it is your responsibility to ensure they are fitted and used properly.