NTA Regional Models, Ireland
The Regional Modelling System (RMS) is the strategic transport planning tool used by the National Transport Authority (NTA) in Ireland. The system is based on a classic transport modelling four-stage model framework, used to forecast future year transport demand based on population and employment scenarios and assign it to networks and services. The model is composed for two distinct elements:
- National Demand Forecasting Model - is a single national system that provides estimates of the total daily travel demand for each of the Census Small Areas. Trip generations and attractions are related to zonal attributes such as population, number of employees and other land-use data.
- Regional Multi Modal Models - 5 Regional Multi-modal Models which estimate mode and destination choice, as well as undertake assignment for road, public transport, walking, and cycling networks at a region-specific level. Models includes a detailed representation of the impact of destination parking availability and cost on these choices, as well as the impact of tours in understanding the true costs of decision making.
The Regional Multi Modal Models have the following main components:
- Trip End Integration Model - takes outputs from the National Demand Forecasting Model and converts them into the appropriate zone system and time period disaggregation
- Full Demand Model (FDM) processes all-day travel demand and outputs origin-destination travel matrices by mode for each time period.
- Highway Model assigns demand to the road network and includes capacity constraint, traffic signal delay and the impact of congestion.
- Public Transport and Active Modes Models assigns the modal demand to the Public Transport, walk and cycle networks. The PT Model includes the impacts of crowding on people’s travel behaviours.
- Secondary Analysis Module - an integrated suite of tools used for the assessment of environmental, safety, health, economic and social impacts of transport schemes.
The NTA Regional Models have been utilised for a range of applications including:
- Cycle Propensity Scenarios – core model adapted to provide information on the impact of attitudes to cycling previously not captured in traditional four stage transport models to assess the levels of cycling, route choice and impact on other modes for a range of cycling schemes/strategies.
- Regional Carbon Assessments- identifying the climate impact of transport and preparing a quantified toolkit of measures to reduce carbon and achieve NET Zero
- Scheme Appraisal and Business Case Development – scheme options appraisal and funding assessments for highway, LRT, Bus and active mode schemes
- Spatial Strategy Assessments – consideration of the transport impacts of land use and growth and the identification of multi-modal transport strategies to facilitate this growth.