Project Application Guidelines for National Roads Unit Transport Modelling Overview

Transcription

1 Project Application Guidelines for National Roads Unit Transport Modelling Overview October 2016

2 TRANSPORT INFRASTRUCTURE IRELAND (TII) PUBLICATIONS About TII Transport Infrastructure Ireland (TII) is responsible for managing and improving the country s national road and light rail networks. About TII Publications TII maintains an online suite of technical publications, which is managed through the TII Publications website. The contents of TII Publications is clearly split into Standards and Technical documentation. All documentation for implementation on TII schemes is collectively referred to as TII Publications (Standards), and all other documentation within the system is collectively referred to as TII Publications (Technical). Document Attributes Each document within TII Publications has a range of attributes associated with it, which allows for efficient access and retrieval of the document from the website. These attributes are also contained on the inside cover of each current document, for reference. TII Publication Title Project Application Guidelines for National Roads Unit Transport Modelling Overview TII Publication Number Activity Planning & Evaluation (PE) Document Set Technical Stream Document Number Project Appraisal Guidelines (PAG) Historical Reference Publication Date October 2016 PAG Unit 5.0 TII Publications Website This document is part of the TII publications system all of which is available free of charge at For more information on the TII Publications system or to access further TII Publications documentation, please refer to the TII Publications website. TII Authorisation and Contact Details This document has been authorised by the Director of Professional Services, Transport Infrastructure Ireland. For any further guidance on the TII Publications system, please contact the following: Contact: Standards and Research Section, Transport Infrastructure Ireland Postal Address: Parkgate Business Centre, Parkgate Street, Dublin 8, D08 DK10 Telephone: infopubs@tii.ie

3 TRANSPORT INFRASTRUCTURE IRELAND (TII) PUBLICATIONS TII Publications Activity: Stream: TII Publication Title: TII Publication Number: Planning & Evaluation (PE) Project Appraisal Guidelines (PAG) Project Application Guidelines for National Roads Unit Transport Modelling Overview Publication Date: October 2016 Set: Technical Contents Table 1. Overview PAG Unit 5.1: Construction of Transport Models PAG Unit 5.2: Data Collection PAG Unit 5.3: Travel Demand Projections PAG Unit 5.4: Transport Modelling Report... 5 Page i

4 1. Overview The collection of Units within PAG Unit 5 provides guidance on transport modelling in relation to National Road projects. The sub-units are as follows: Unit 5.1: Construction of Transport Models; Unit 5.2: Data Collection; Unit 5.3: Travel Demand Projections; and Unit 5.4: Transport Model Report. This Unit provides the reader with an outline summary of the remaining sub-units allowing the reader to understand the role of each unit within the transport modelling process. Page 1

5 2. PAG Unit 5.1: Construction of Transport Models PAG Unit 5.1 specifies the process involved in the preparation of a transport model. The guidance introduces the conceptual role of transport models and their application and outlines the underlying assumptions, software packages and data considerations involved in four classifications of transport model, namely: Variable Demand Models; Assignment Models; Microsimulation Models; and Simple Models. The importance of defining the scope of a modelling exercise in order to choose the correct model is highlighted and precise details are provided regarding the process of constructing a base year model to reflect transport demand and supply as well as guidance on subsequent model calibration and validation. Page 2

6 3. PAG Unit 5.2: Data Collection PAG Unit 5.2 documents the data sources and survey approaches used to develop transport models. Particular attention is paid to finding a balance between costly data collection and the level of model accuracy required. Emphasis is placed on the need to review existing sources of information, including previous transport models, prior to survey commencement. The guidance highlights the importance of effective models to aid decision-making but also surmises that the quality and quantity of data collected will often reflect the scale of the project being assessed. The reader will understand the key elements of a transport model, the range of existing data sources and the different methods of data collection utilised in the creation, calibration and validation of transport models. Page 3

7 4. PAG Unit 5.3: Travel Demand Projections PAG Unit 5.3 provides guidance on the preparation of future travel demand projections for use in the appraisal of National Road projects. The unit outlines the role of national travel demand projections and the need for consistency in the appraisal of transport schemes. The role of the TII National Transport Model in providing outputs to inform future projections is also discussed. Two methodologies for projecting travel demand for National Road projects are outlined and discussed: Link-Based Growth Rates (Simple Models); and Zone-Based Growth Rates (Assignment and Variable Demand Models). Page 4

8 5. PAG Unit 5.4: Transport Modelling Report PAG Unit 5.4 describes the structure and content of the information to be provided in the Transport Modelling Report (TMR). The TMR is a key deliverable of the appraisal process and documents the development, calibration and validation of the base year transport model alongside the data collected in order to construct the model. The TMR clearly outlines the growth projections used and any assumptions in relation to the allocation of growth. The impact of the scheme is discussed and presented through graphical and tabular outputs. Guidance for completing the TMR is supplemented by visual examples and a detailed check-list to ensure the reader fully understands the reporting requirements. Page 5

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