Passenger transport demand, fuel consumption, and emissions data for the Irish Passenger Transport Emissions and Mobility (IPTEM) model

These data and analyses support the research article “How and Why We Travel – Mobility Demand and Emissions from Passenger Transport (O'Riordan et al., 2022). This article refers to a spreadsheet model, the Irish Passenger Transport Emissions and Mobility Model (IPTEM V2.9). The spreadsheet model is available for download from Zenodo (O'Riordan et al., 2022). The model and the underlying data, details the passenger transport demand by trip purpose (work, shopping, education etc.,), mode type (car, rail, bus, cycling, walking) and trip distance for Ireland over the period of 2009–2019. Passenger occupancy rates for public transport modes in Ireland, CO2 emissions intensities and annual CO2 emissions are also included in the Data in Brief. Assumptions and equations used to develop the IPTEM V2.9 are available in the Experimental design, materials, and methods section.

Engineering Specific subject area Passenger transport demand and CO 2 emissions in Ireland Type of data Table  Chart Figure How the data were acquired • National transport survey data gathered from Central statistics office (CSO) [3] • Information from the Irish Car Stock Model V 2.4 on an online repository [4] • Calculations as mentioned in the Data in Brief's reference paper and outlined in further detail in Experimental design, materials, and methods equations: Eqs. (1)- (10).

Data format Raw Analyzed Description of data collection
• Irish Car Stock Model, retrieved from an online repository [4] , referred to in a Data in Brief [5] that provides technological stock data of car characteristics such as stock, mileage, and energy consumption per kilometre. • Population data made available from Eurostat [6] • National Travel Survey Data is available from the Central Statistics Office [

Value of the Data
• This data provides clarity behind the modelling assumptions and methods used to model passenger transport demand and emissions in Ireland. • While the data is Ireland specific, it serves as a guideline for the scientific community to ways to replicate similar modelling methods designed for other regions at a local, national, or international level. • It provides valuable insights into the sources available at a national level which most European member states have freely available, and which can be used to replicate the modelling methods provided in the accompanying Transportation Research Part D article [1] . This data can be used to gain insights into the link between modal shift to low carbon dioxide passenger transport.
• Energy analysts can benefit from the detailed passenger transport demand information, serving to aid in replication of transport emissions and demand analyses. Policymakers also benefit from the information on occupancy rates, CO 2 emissions intensity and passenger transport demand listed.

Data Description
The dataset referred to in this article exists as an Excel spreadsheet available on Zenodo [2] . The spreadsheet model has a series of sheets contained within the Excel file 'IPTEM V2.9'. The dataset within this article provides secondary data from the Irish National Travel Survey conducted by the Central Statistics Office [7] , data from the Irish Car Stock Model [ 4 , 8 ], energy and emissions conversion factors from the Sustainable Energy Authority of Ireland [9] . Occupancy, annual energy consumption figures, and passenger numbers from public transport providers: Dublin Bus (city bus transportation system) [10] , Irish Rail (national rail network in Ireland) [11] , Bus Éireann (national bus network in Ireland) [12] , and Luas (light rail system in Dublin, Ireland) [13] , are also included. Assumptions underpinning the IPTEM V2.9 model are also shared in the sheet "PKM (Passenger Kilometre) Calculation Assumptions". Calculations for passenger kilometre demand in Ireland by trip purpose, trip distance and mode type are found in "PKM distance by distance and mode", "PKM by distance and journey type" sheets. Excel formulae and references to previous sheets are embedded in the calculation sheets. Calculations for CO 2 emissions by trip distance, mode type and trip purpose are found in Excel sheet "CO 2 Emissions Intensity" and "CO 2 Emissions by mode, purpose and distance". An index and content description of the sheets in the IPTEM V2.9 model is listed in Table 1 . This Data in Brief contains sample rows and entry values to describe the tables in the repository. The sample table entries are included in the data in brief to assist navigation of the accompanying Excel spreadsheet repository.

CSO tables
The CSO tables are based on the National Travel Survey conducted by the Central Statistics Office (CSO). The survey was conducted for Ireland and is based on travel diaries by respondents in 2009, 2012, 2013, 2014, 2016 and 2019. Data for the intervening years is interpolated. A description of the mode types available in the survey is listed in Table 2 .
Passenger kilometres, occupancy figures, energy, and CO 2 emissions intensity per passenger kilometre serviced are determined for the following public transit authorities in Ireland   [8,4] . Data is referred to in Table 27 -Table 34 Trip distance categories from the National Travel Survey were as follows: The average of each of the categories are used in calculating overall Passenger Kilometre demand. The figure for passenger kilometres for the > 8 km category was calculated through calibration with the Irish Car Stock Model. Table 2 Overview of transport modes referred to in the IPTEM model [1] .

Mode Description
Private Car -Driver People travelling in a car as the main driver Private Car -Passenger People travelling in a car driven by another person Walk People walking, this is also categorized as an "active mode" of transport

Bus
People taking the bus, there are two main bus transit providers in Ireland, Dublin Bus, which operates urban driving style city routes in Dublin, Ireland, and Bus Éireann, which provides a mix of urban and intercity driving. Private bus transport is assumed to be negligible. Cycle Includes the use of both mechanical bikes and e-bikes for cycling and is also categorized as an "active mode" of transport Rail/DART/Luas This mode choice refers to the three rail providers in Ireland; Irish Railwhich operates long distance rail in Ireland, DART-the Dublin Area Rapid Transit, a commuter rail operating in the Greater Dublin area and Luas -a city light rail which operates in Dublin Taxi/hackney People travelling in a car operated by a registered taxi driver Lorry/Motorcycle/Other This mode includes lorries, motorcycles and any other mode choice not included in the preceding categories   Table 9 Population, 2009-2019, Source: Eurostat [6] .

Irish car stock model V 2.4
The tables listed in the sheet "Irish Car Stock Model V2.4" are extracted from an open source model [4] . A Data in Brief article corresponding to elements of an earlier version of the Irish Car Stock Model is available [5] . The methodology behind the calculation of vehicle kilometres and fuel consumption of private vehicles in Ireland is based on a study on technology stock modelling of private cars in Ireland [14] .   Table 35 Occupancy Public Transport, based on passenger kilometres (Table 34) and Vehicle kilometres ( Table 39 ).

Table 47
Energy Intensity by Fuel Type -Luas (kWh/km) calculated from fuel consumption (Tables 40-42) and passenger kilometres (Table 36).              Table 3 Distribution of journeys by mode of travel and distance < 2 km, 2009-2019 % 40 Table 4 Distribution of journeys by mode of travel and distance 2-4 km, 2009-2019 % 0 Table 5 Distribution of journeys by mode of travel and distance 4-6 km, 2009-2019 % 0 Table 6 Distribution of journeys by mode of travel and distance 6-8 km, 2009-2019 % 0 Table 7 Distribution of journeys by mode of travel and distance > 8 km, 2009-2019 % 0 Table 8 Average Journey Length km 1.00 Table 14 Mode distance adjustment factor 1.0 0 0 1.6. Passenger kilometres by distance and purpose Table 69 Sample entry row passenger kilometres by trip distance and purpose with additional reference row for  Table 3 Distribution of journeys by mode of travel and distance < 2 km, 2009-2019 % 13 Table 16 Distribution of journeys by purpose of travel and distance 2-4 km, 2009-2019 % 0 Table 17 Distribution of journeys by purpose of travel and distance 4-6 km, 2009-2019 % 0 Table 18 Distribution of journeys by purpose of travel and distance 6-8 km, 2009-2019 % 0 Table 19 Distribution of journeys by purpose of travel and distance > 8 km, 2009-2019 % 0 Table 20 Average Journey Length 1.00 Table 21 Trip purpose distance adjustment factor 1.0 0 0

Experimental Design, Materials and Methods
This section will discuss the methods used to acquire the secondary data and calculate the primary data used in the IPTEM V2.9 spreadsheet.

Acquisition of secondary data
This section outlines the steps required to acquire, process, and analyse the data referenced in this article.
The National Travel Survey conducted by the CSO [7] forms a key source of secondary data for the "CSO Tables" sheet in IPTEM V2.9. The data was extracted from the interactive data tool available from the Central Statistics Office [3] .
The open-source Irish Car Stock Model formed the basis of on the secondary data included in the "Irish Car Stock Model V2.4" spreadsheet [4] . The Irish Car Stock Model as described in Daly and Ó Gallachóir develops a picture of private car energy demand in Ireland [8] . The study documents the method and data needed to create a bottom-up private vehicle technology stock for Ireland. A Data in Brief corresponding to the Irish Car Stock Model is available [5] .
Figures for the energy consumption, vehicle kilometres and passenger numbers for public transport operators in Ireland were extracted manually from Annual Reports by Luas [13] , Bus Éireann [12] , Irish Rail [11] , and Dublin Bus [10] . These figures were referred to in "Occupancy, Energy Consumption and Emissions" sheet.

Equations for primary data
In this section, equations for the calculation of the primary data listed in the IPTEM V2.9 model are defined. The equations are previously referenced in the Data Description section as the method used to calculate values in table entries.
The CSO distance categorization does not account for mode types that typically service distances on the shorter end of the distance grouping. Distance weighting factors based on mode are calculated by comparing average distance travelled by that mode with the "Private cardriver" mode as shown in (xxx).  Total Passenger Kilometres for a given distance and mode category is calculated as a function of the share of journeys by distance and the share of journeys that are of that mode type, then applying the average distance by the kilometer grouping and applying weighting factors based on the mode type as calculated in Eq. (1). To calculate total passenger kilometres by distance and trip purpose, the method used in Distance weighting factors based on trip mode are applied to adjust the average distance calculated to reflect the average journey lengths given for a given trip mode [1] . Weighting factors based on trip purpose are also applied and calculated by comparing the average distance of journeys by trip purpose Passenger kilometres by trip purpose was calculated as shown in Eq. (4). Weighting factors based on trip purpose are also applied to adjust the average distance calculated to capture the varying average journey lengths for certain trip purposes [1] . Only figures from 2009 are available as average distances based on trip purpose are given from the 2009 National Travel Survey.

Eq. (3): Total Passenger Kilometres
Average distance based on trip purpose and mode type is based on the average distance based on trip purpose type ( Table 21 ) and average distance based on mode type ( Table 59 ) The share of passenger kilometres for that year by distance, mode type and trip purpose, as listed in Table 69: Sample entry row passenger kilometres by trip distance and purpose with additional reference row for Where: • f is the fuel type • t represents the transit provider.
Energy consumption of a given journey type by mode, trip purpose or trip distance is calculated as a function of the mode type's energy intensity and the passenger kilometres serviced by the journey's passenger kilometres for the specified trip purpose, distance, and mode.
Eq. (8) Where: • f is the fuel type • t represents the transit provider.
CO 2 emissions intensity per kWh were based on the Sustainable Energy Authority of Ireland conversion rates [9] .
Annual energy consumption values for private vehicles were derived from the Irish Car Stock Model [4] , annual energy consumption values for bus, heavy rail and light rail were derived from national public transport annual reports [10][11][12][13] .
Total CO 2 emissions ( Table 75 ) is calculated as a function of the passenger kilometres by the given mode type, trip purpose and trip distance and the CO 2 emissions intensity of the given mode type, trip purpose and passenger kilometre category ( Tables 48-51 ).
The equation for total CO 2 emissions is outlined in Eq. (10).

Ethics statements
The authors have no conflicts of interest to declare. Ethics approval was not required for this data in brief.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.