A New Emme Implementation of WebTAG-Compliant Greater Bristol Modelling Framework with SATURN

1. A New Emme Implementation of WebTAG-Compliant Greater Bristol Modelling Framework with SATURN Yanling Xiang, Ian Wright, Tony Meehan (Atkins) The West of England Partnership 11th November 2008

2. GBMF Modelling Framework Outline of Presentation • Overview of GBMF 2. The GBMF Demand Model in Emme 3. The GBMF PT Emme Model Based on SATURN 4. GBMF Forecasting

3. 1. Greater Bristol Modelling Framework (GBMF) - Overview

4. G-BATS3 G-BATH G-NS GBMF Modelling Framework The Greater Bristol Area Sub-region covered by: • Bristol City • Bath & North East Somerset • North Somerset • South Gloucestershire Three Multi-Modal Models: • G-BATS3 (600 zones) • G-BATH (453 zones) • G-NS (418 zones)

5. GBMF Modelling Framework GBMF – Three Transport Models G-BATS3 G-BATH G-NS

6. GBMF Modelling Framework GBMF – Development Criteria • Provide common modelling approach across the Greater Bristol Area • Develop transport models fully compliant with WebTAG: • TAG Unit 3.10 – Variable Demand Modelling • TAG Unit 3.11 – Modelling Public Transport Schemes • TAG Unit 3.12 – Modelling & Appraisal for Road Pricing • Provide a range of standardised forecasting scenarios • TAG Unit 3.15 - Treatment of Uncertainty in Forecasting • Technical liaison with Department for Transport • Support for TIF & Major Scheme Bids

7. Public Transport • EMME2 v9.3 • Demand Model • EMME2 v9.3 • Reporting • ArcView v9.2 & MapInfo v9.0 GBMF Modelling Framework Standard Modelling Tools • Highway Models • SATURN v10.8.17

8. GBMF Modelling Framework GBMF – Applications • Current model applications: • Road User Charging Proposals and TIF Complementary Measures • Bus Rapid Transit 2 Major Scheme Bid (MSB) • South Bristol Link Road MSB • Weston Package MSB • M32 Park & Ride Proposals • Other packages

9. 2. The GBMF Demand Model in Emme – Fully Compliant to WebTAG

10. GBMF Modelling Framework Model Responsiveness • Transport models attempt to represent and forecast travel decisions and behaviour: • In Real LifeComponents of the Transport Model • to own a car • to make a trip • for which purpose • to where • by which mode • at which time • by which route Trip Generation / Attraction Demand Model Trip Distribution Mode Choice Time Period Choice Assignment Supply Models

11. Frequency Main Mode Choice Car / P&R Public Transport Time period Choice Time Period Choice Destination Choice Destination Choice Sub Mode Choice Sub Mode Choice Rail Bus / BRT Car P&R GBMF Modelling Framework GBMF Demand Hierarchy 24-Hour Demand (by segment) Travel demand in each modelled time period

12. By Household Car Ownership (2) Non Car Available, Car Available (Car 1+) By Income: Value of Time (3) All Non-Work Trips: <=£17,500 <=£35,000 >£35,000 By Trip Purpose (5) HBW: Commuting HBEB: Home-based Emp. Bus. HBO: Home-based Other NHBEB: Non Home-based Emp. NHBO: Home-based Other Demand Segments By Road Vehicle Types (3) Car (Note: LGVs & HGVs in assignment only) By Modes (4) Car Bus / BRT Rail Park & Ride GBMF Modelling Framework GBMF Segmentation Supply Segments: PT = 1 Highway = 6

13. GBMF Modelling Framework GBMF Modelling Structure

14. GBMF Modelling Framework GBMF Demand Model Summary • WebTAG compliant incremental hierarchical logit model • 24hr Production-attraction modelling framework • “Pseudo tour” for time period choice • Realism tests and sensitivity tests • Fuel cost elasticity test • Journey time elasticity test • PT fare elasticity test • Outturn elasticities are Satisfactory by DfT • Automated running procedures controlled by Emme batch • Extensive model outputs ready for • TUBA and other post-assessment studies

15. 3. The GBMF PT Emme Model – Based on SATURN Highway Model

16. GBMF Modelling Framework PT Model Linked to SATURN PT network SATURN network SATURN network overlaid onto the PT network – only difference is in the walk link and Rail links

17. GBMF Modelling Framework GBMF Bus Network Development • Bus Network • MUST BE IDENTICAL IN STRUCTURE TO SATURN HIGHWAY NETWORK FOR ATTRIBUTES TO BE PASSED ACROSS • Nodes – SATURN dat file • Links – dump out link lengths using SATDB • Centroid connectors • Need not be identical to highway CCs • Bus journey time • Free-flow SATURN link time if bus only link • Congested SATURN link time if congested • SATURN turn time • Delay: 20 Sec per bus stop • @bsd (bus stop density) • @svd (Selective vehicle detector) • Preserve base calibration / validation

18. GBMF Modelling Framework Link to SATURN Highway Model

19. GBMF Modelling Framework Emme Batch to Call SATURN Runs Input AM, IP and PM network files Create AM, IP and PM Matrices AM Pre Peak Assignment Inter Peak Assignment PM Pre Peak Assignment AM Peak Assignment AM Peak Skims Inter Peak Skims PM Peak Skims Import into Emme for next loop

20. 4. The GBMF Model – Forecasting

21. GBMF Modelling Framework Incremental Forecasting – Inputs / Outputs Changes in Demand (24hr daily level) GBMF Transport Model Reference Costs (Base Year) Forecast Supply Forecast Demand

22. GBMF Modelling Framework Forecasting • Assesses current & future travel demand and conditions across the transport network • Forecast impacts arising from: • Growth in the Demand for Travel • Spatial Development (housing / employment) • Demographics • Car Ownership • Economy • GDP • Fuel costs • Average Earnings etc • Infrastructure • New build / upgrade • Network Management • Bus Rapid Transit Schemes • Expansion of Park & Ride sites