Ireland’s Regional Modelling System – Modelling Parking Within Ireland’s Cities

Ireland’s Regional Modelling System – Modelling Parking Within Ireland’s Cities


Barry Colleary, National Transport Authority, David Siddle, Jacobs, Diarmuid Bailey, Systra


A description of the Park-and-Ride, workplace parking and parking distribution modules that form a key part of Ireland's Regional Modelling System


The National Transport Authority (NTA) has a national transport planning remit with responsibilities which include strategic transport planning and the provision of public transport infrastructure and the regulation of PT services. Jacobs and Systra were commissioned in 2012 to support the NTA in developing and enhancing its transport modelling capabilities. The aim of the commission was to create a “state of the art”, robust and transparent regional modelling system that could be implemented at an appropriate scale for each of the five city regions within the NTA’s remit. The NTA’s new Regional Modelling System (RMS) was complete in 2016 and is comprised of five large regional models, linked by a National Demand Forecasting Model.
One of the critical issues within Ireland’s cities is congestion caused by high car mode share, which in turn can be attributed to the high number of parking spaces. It has been recognised that future transport strategies will need to consider ways to limit the availability of car parking to tackle this issue, and the RMS will need to be able to model parking with a high level of detail to allow those strategies to be appraise.
This paper looks at the methodologies behind the three Parking Models within the RMS: Park-and-Ride; workplace parking, and; parking constraint and distribution. The Park-and-Ride model will be most familiar to readers and determines the site choice of Park-and-Ride users. The workplace parking model captures the effect of widespread, free parking at workplaces and colleges on mode choice. Finally, the parking constraint and distribution module has two functions: firstly, it captures the additional costs of parking that arise as the parking demand approaches capacity, and secondly, it provides a mechanism within the model to allow car users to choose to park in a zone which is remote from their destination and walk between the two.


Association for European Transport