International visitors going on the interisland ferry while travelling in New Zealand

International visitors: persons who travel to a country other than that in which they have their residence, but outside their usual environment, for a period not exceeding 12 months and whose main purpose of visit is other than the exercise of an activity remunerated from within the country visited'.

People are counted for EACH transport method mentioned in the survey. Visitors are likely to use multiple modes of transport throughout their trip.

https://www.mbie.govt.nz/immigration-and-tourism/tourism-research-and-data/tourism-data-releases/international-visitor-survey-ivs/

Survey data is collected online. To produce accurate estimates, the survey was designed to meet a 5 per cent margin of error for the total annual expenditure and a 10 per cent relative margin of error (RME) for each of the top 6 country markets.
To achieve these margins of error, a minimum of 8,900 international visitors to New Zealand are sampled per year. The sample also has target allocation sizes for each of the top six markets to ensure that there are enough respondents to meet the 10 per cent threshold.

Data from the International Visitor Survey is subject to very high sample error. Caution should be exercised for weighted visitor counts of 20,000 or less. Surveyed visitor count information, derived from the raw number of respondents completing the questionnaire, has been included with the weighted visitor counts as an aid for data quality interpretation.

The population of interest excludes:
- individuals who reside in New Zealand (New Zealand was their last place of residence for twelve months or more)
- individuals who have been in New Zealand for longer than 365 days
- those in transit who have not formally entered New Zealand (they have not filled out an arrival card and handed it into Customs)
- individuals who visit New Zealand to serve in the armed forces, for diplomatic or consular business, or aircrew on duty or between flights
- individuals whose next country of permanent residence is New Zealand.

The target population also excludes:
- Those aged less than 15 years because parental consent is required to interview those under 15, and this is not practical at the interview screening stage.
- Those whose primary purpose of visit were to attend a recognised educational institute and will be foreign fee paying students. The spending of this group is estimated separately as their spending patterns are significantly different from other international visitors, which can create problems in calculating estimates of total spend.

At URL provided, select "International Visitor Survey: Transport", customise the data by choosing 'YE Jun 2019' for the Year ending variable and selecting all the remaining variables.

The International Visitor Survey (IVS) measures the expenditure, behaviour and characteristics of international visitors to New Zealand.
Data includes expenditure, places visited, activities/attractions, accommodation and transport.

Data provides information about the different types of transport used by international visitors during their stay in New Zealand.

The sampling schedule is constructed to include international visitors to New Zealand departing from Auckland, Wellington, Christchurch and Queenstown international airports. Each day in the quarter is split into time periods.
For Auckland, Wellington and Queenstown airports two hour time periods are used, while for Christchurch airport it is a four or five hour time period. The probabilities of a time period being selected are based on the number of flights during that period over the previous year (periods with no flights will have no probability of being selected while those with a high number of flights have a high probability).