Irish National Transport Model: A feasibility analysis - Ian Williams

IRISH NATIONAL TRANSPORT MODEL: A FEASIBILITY ANALYSIS Ian Williams EPA Transport Seminar, Dublin Oct 14, 2011IAN WILLIAMS 1

THE STUDY• Clients • Environmental Protection Agency • Department of Transport • National Transport Authority• Study Aims: • Examine the feasibility of developing a National Transport Model (NTM) for Ireland • Specify in outline the methodology and the model structure • Create a design to enable the NTM to meet a wide range of requirements • Provide a temporal roadmap for developing the model and for enhancing it through time• WSP Team: Ian Williams, Clare Lindsay, Gordon Deane, Duncan Forbes• Duration: September 2010 – January 2011IAN WILLIAMS 2

MAIN CONCLUSIONS• The work undertaken demonstrated that • Developing an NTM for Ireland would certainly be feasible • Many of the issues of scale encountered in other countries are reduced for Ireland • Much of the data and information required already exists • Much of the rest could be obtained at a feasible cost• The background findings leading to these conclusions are outlined in the rest of this presentationIAN WILLIAMS 3

MAIN STAGES OF THE STUDY –TECHNICAL NOTES1. Inventory of models2. Inventory of transport data3. Workshop to assemble user requirements4. Review of best practice in national modelling outside Ireland5. Structure and functionality of the NTM6. Road map for development and enhancement7. NTM in an All-Island context8. Managing and maintaining the NTMIAN WILLIAMS 4

INVENTORY OF IRISH MODELS• Make maximum use of relevant data from existing models• Maximise consistency with existing models • avoid unnecessary differences• Facilitate interfacing to NTM of other models • Main input data flow from others to NTM • Main output results flow from NTM to others • All models retain operating independence • exchanges are through external files not internal structures• The NTM should complement more than replace other existing modelsIAN WILLIAMS 5

MAIN MODELS CONSIDEREDMODEL TYPEGreater Dublin Area (GDA) Transport Model Transport modelNational Traffic Model (NRA-NTM) Transport modelRail Procurement Agency (RPA) Transport Model Transport model Transport policy modelTREMOVE and GAINS (no network)MOLAND Land use modelCork Area Strategic Plan (CASP) Transport modelGalway Transport modelLimerick Transport modelIAN WILLIAMS 6

INVENTORY OF TRANSPORT DATA –POTENTIALLY AVAILABLE• Census – demographics, commuter & education travel demand• Modal networks from NRA-NTM and city region models• HGV movements from NSTGR• Rail, port and airport movement data from CSO / Operators• Road vehicle stock from DoT• Energy / emission functions from research and TREMOVEIAN WILLIAMS 7

INVENTORY OF TRANSPORT DATA - GAPS• Discretionary travel demand: • GDA Household Survey is useful - but • QNHS – needs expansion in sample and coverage• Light Commercial Vehicle Survey • similar in structure to NSTGR but 5-yearly not annual • absence of good LCV data is an issue in most countries• HGV fuel use • straightforward extra questions in existing NSTGR• Filling these gaps early would be very beneficialIAN WILLIAMS 8

NTM IN AN ALL-ISLAND CONTEXT• Model needs to take suitable account of developments in NI: • Through trips and external movements of passengers and freight • Impacts of infrastructure investment within NI • Increasing integration of logistics and businesses on the Island• Ensure information flow regarding any future NI NTM developments• DATA ISSUES• Potential inconsistencies between data definitions• Availability of data on demand characteristics of external movements • particularly N2/A5 and M1/A1 corridors from Road Service NI• Cross-traffic at ferries and airportsIAN WILLIAMS 9

WORKSHOP ON USER REQUIREMENTS• Main focus of NTM is inherently different to that of other models• Should adopt and promulgate • national and local planning assumptions which are consistent across the whole of the country• A multimodal transport model encompassing all travel modes including: • walking and cycling • passenger and goods movements • national and international movements• Should provide indicators for use to examine policies for: • emissions, economic growth, land use planning, congestion managementIAN WILLIAMS 10

REVIEW INTERNATIONAL BEST PRACTICE: 1• Need to develop the model in a manageable amount of time, • maintain momentum• There is a continuing need for balance in trade-offs: • between sophistication plus theoretical purity • versus achievability, run times and ease of model use • in the level of detail achievable in individual model components• All large models are internally constructed as a collection of sub-models• Hence there is an overriding need • to specify robust, consistent interfaces between modules • to ensure that segmentation is maximally consistent across modules.IAN WILLIAMS 11

REVIEW INTERNATIONAL BEST PRACTICE: 2• The theoretical basis of passenger modelling is relatively well researched• The number of successful freight models in use is smaller than the number of passenger models• Greenhouse gas and other emissions modelling should be based on • up to date data about vehicle stock, fuel consumption and emission rates specific to different transport contexts• All widely used models reviewed had a “main” consultant organisation that • led the design and construction • has continued to have a key role in upgrading it • even if the model running or applications are done by client usersIAN WILLIAMS 12

IMPLEMENTATION WARNINGS TO EMPHASISE• Avoid over complex design • but ensure that the design is complete and relatively future proof• Be aware (beware) of inconsistency between national model and regional tier models• Using too many consultants to build the model can result in • a design which is difficult to get working in an integrated way • the procurement approach is of critical importance• If the model is hard to use or overly expensive to run • it may fall into disuseIAN WILLIAMS 13

Potential trip end and Spatial Travel Demands planning data tool • Trip Ends • Car Ownership Planning outputs STRUCTURE AND • Housing takeup • Floorspace takeup FUNCTIONALITY OF NTM National changes • GDP National Transport Model • Demographic Local inputs Car Ownership Vehicle Stock • Housing Planning and Location Model Model Model • Employment Floorspace • Schools • Leisure Passenger Demand Model Assignment Analysis Suite• Economic and trade growth by Model industrial sector• Rail and costal shipping scenarios• Logistics scenarios (eg warehouse construction) Freight Demand Model• Household an population forecasts • Highway(roads, charges, Environmental Sub-Model capacity, speed) • Greenhouse Emissions • PT fares and Services • Pollutants Outputs • Parking Transport and travel • SMART measures • Congestion Inputs WILLIAMS • Fuel prices • Mode share IAN • Distance travelled 14

OVERVIEW OF PROPOSED INITIAL MODELIAN WILLIAMS 15

ROAD MAP FOR NTM DEVELOPMENTIAN WILLIAMS 16

MANAGING THE NTM DEVELOPMENT• Software choice • may well need multiple packages• Licensing and IPR • limit the number of different packages and licences required • Ensure IPR for new developments remains with NTM client• Documentation • never receives sufficient emphasis or resource• Training • complex due to necessary ambitions of an NTM• Modularity and multi-vendor development • Controlling a multivendor model development process requires particular management skills from the Client Group • to avoid clashes in approach and gaps between the systemsIAN WILLIAMS 17

MAINTAINING THE NTM• Needs a clear program and an adequate budget for maintenance and updating: • components of the model to extend its functionality or improve its performance • data inputs to model (e.g. future Census) • version control and documentation of model updates • management of policy results when model versions change • don’t change official versions too often• Continuity in • the team of users • the team of developers or model updatersIAN WILLIAMS 18

QUESTIONS?IAN WILLIAMS 19

Irish National Transport Model: A feasibility analysis - Ian Williams

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