National Travel Survey 2012 and 2013

Reference period

The 2012 and 2013 National Travel Survey (NTS) was included as a module to the QNHS in the 4th quarter of 2012 and 2013. The travel reference days, i.e. the days for which travel data was collected, covered the periods October 7^th 2012 – January 5^th 2013 and October 5^th 2013 – January 4^th 2014 respectively.

Questionnaire

A copy of the questionnaire used in this module is available here: NTS questionnaire.

Key definitions and descriptions

Population: Refers to adults, aged 18 and over, resident in the Republic of Ireland.

Journey: A journey is defined as a one-way course of travel for the purpose of carrying out a specific activity. Return trips were recorded as separate journeys. To be relevant to the survey journeys must have:

• Commenced in the travel reference day (it may end the following day)
• Comprise exclusively of domestic travel (all stages of foreign travel are excluded)
• Not be an integral part of a respondent’s routine employment (e.g. a milkman on his milk round, a taxi driver picking up a fare, etc.)

Journey purpose: The purpose of a journey is governed by what action was taken at the end of the journey.

Mode of travel: Where a journey consists of more than one mode of travel, the main mode of travel is determined by the mode of travel used for the greatest distance. In the event of there being more than one main mode of travel (i.e. when two or more modes are of equal distance), then the main mode of travel is determined by the mode of travel used for the earliest stage of the journey.

Journey duration: This is calculated as the sum of time spent on each stage of the journey and not the difference between the start and end time of a journey.

Degree of urbanisation (degurba) classification

This classification is created from an aggregation of population density estimates derived from the Census of Population. The categories included in each aggregate are explained below:

(1) Thinly populated area refers to rural areas

(2) Intermediate density area refers to towns and suburbs

(3) Densely populated area refers to cities, urban centres and urban areas

Grossing

The QNHS grossing procedure aligns the distribution of persons covered in the survey with independently determined population estimates at the level of sex, five-year age group and region. The grossing factors applied in the processing of the NTS results were calculated in the same manner but differ from those that were used in the preparation of the main QNHS estimates as the NTS questions were asked to a sub-sample (persons aged 18 and over) of the overall QNHS sample.

Respondents to the survey

Only direct respondents aged 18 and over were included in the NTS survey (i.e. no third party responses were permitted for the NTS module.

Guide to using the NTS results

Care should be taken when interpreting the results or when comparing them with the POWCAR and other data sources. When comparing the NTS to POWCAR data, it should be noted that the NTS journey purpose of ‘work’ includes both commuter and business travel while the POWCAR data includes commuter travel only; the NTS collected travel data for a specific day while the Census collected travel data for the ‘usual’ journey to work, school or college. Similarly, when examining issues such as the mode share for travel to school/education, it is important to note that the NTS doesn't accurately reflect the mode share for the whole student population as the NTS only sampled persons aged 18 and over.

Data from other international sources/surveys indicates that there can be significant seasonal variations in travel patterns. The NTS travel reference days spanned the Christmas and New Year holiday period when travel patterns may be atypical. This period also encompasses the shortest days and some of the coldest and wettest weather of the year. Estimation of survey results from data relating to only one day’s activity for a sample of journey introduces a statistical variability which would not be present if a full year’s data had been collected for every journey.

Note on tables

The row or column percentages in tables may not add to 100% due to rounding.