Laser Enhancement Project
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Laser Enhancement Project Contents Front cover......................................................................................................................2 1. Introduction ................................................................................................................3 2. Modelling approach and zoning................................................................................5 3. Land use model.........................................................................................................15 4. Strategic Transport Model ......................................................................................37 5. Model validation for 1991 and 1997 .......................................................................74 6. Conclusions .............................................................................................................125 7. Bibliography ...........................................................................................................129 8. Glossary...................................................................................................................130 Appendix 1 : LASER Enhancement Project and its relationship with ORBIT, SERAS and LOIS.......................................................................................................133 Appendix 2: List of LASER 3.0 Model Zones .........................................................138 Appendix 3: Modal split calibration - use of data sources .....................................162 1 Laser Enhancement Project Front cover Final Report (Deliverable D4 Final Release Version) For ITEA Department of Transport, Local Government and the Regions Contract PPAD 9/65/71 (ME&P ref. P959/2) ME&P (Part of the WSP Group) Cambridge May 2002 (Corrections to minor typing errors made July 2003 for DfT web site publication) 2 Laser Enhancement Project 1. Introduction The purpose of this report is to present the LASER Model Version 3.0. This is a MEPLAN-based land use/transport interaction model for a Study Area that covers Greater London and 2 UK Government Office regions around London, i.e. the South East and the East of England. The model includes two main components: a) A land use component, which simulates some key relationships between industries, employed residents, households, and floorspace. This land use component forms the basis on which all residents' travel demand within the Study Area is estimated. b) A strategic transport component which assigns the travel demand of the AM peak to modal networks and estimates the monetary and time-based generalised costs of travel subject to capacity restraint on road and rail-services. These two-model components together simulate the interaction of land use activities and transport supply conditions. The model is intended for use to forecast the future location of land use activities and of transport demand under different policy scenarios, thus providing a consistent basis for assessing the packages of infrastructure schemes and regulatory measures under consideration. Chapter 2 of this report provides an overview of the modelling approach, model structure, and zoning. Chapters 3 and 4 discuss respectively the implementation and calibration of the land use model and the strategic transport model. Chapter 5 describes the model runs of 1991 and 1997, and provides a validation of the model against the observed data that is currently available. Chapter 6 assesses the strengths and weaknesses of LASER3.0, and discusses its use for future policy applications and the scope for further development of some aspects of the model. This LASER Enhancement Project for the ITEA Division of DTLR had the specific task of implementing a limited package of model enhancements designed to be the minimum requirement needed to improve the performance of the model. The work programme aimed to tackle the weaknesses identified by the Laser Model Validation Study (Atkins Wootton Jeffreys and David Simmonds Consultancy, 1997), particularly in those areas where good quality data has become available since the previous version of LASER (i.e. Version 2). The updated and enhanced version of the LASER Model is now labelled Version 3.0. Since the commissioning of the LASER Enhancement Project there have been three further studies which have had a bearing on the design and implementation of LASER3.0 as follows. First, LASER has been chosen as the strategic land use/transport model for the London Orbital Multi Modal Corridor Study (known as Orbit). LASER3.0 is being applied in the Orbit study, within which further extensions to the model have been requested to address the particular needs of that study. These model extensions have been developed in parallel to the LASER Enhancement project. They include a major improvement in the representation of rail and underground services, refinement of the road network characteristics, and a new residential floorspace model. Furthermore, in order to address the needs of Orbit the number of zones was substantially increased beyond that originally envisaged. Since all of these extensions now form an integral part of the LASER model, model extensions are reported here as part of LASER3.0, irrespective of which project originally commissioned them. The main usage of the LASER model in the Orbit study has been to test policy initiatives in the year 2016. This usage is not reported in this report which only presents results for the model runs in 1991 and 1998. Secondly, LASER has been chosen as the strategic land use/transport model for the London-Ipswich Multi Modal Corridor Study (known as LOIS). Since the LOIS study is focused only on the north east sector of the LASER study area, the LASER3.0 zoning structure will have to be altered to suit the LOIS requirements. This has no direct impact on the LASER Enhancement Project. 3 Laser Enhancement Project Thirdly, the South East Regional Airports Study (SERAS) has expressed their interest in using LASER3.0. Special airport zones and an airport employment category have been included in LASER3.0, and the road and rail connections to airports have been coded. Furthermore, since LASER3.0 does not model air travel, SERAS has provided passenger travel and goods vehicle matrices to and from Heathrow, Gatwick, Stansted, London City and Luton airports. LASER3.0 makes use of these road and public transport matrices as an exogenous input in its network assignment procedures. No additional LASER model development is envisaged for SERAS. Appendix 1 provides the details of how LASER3.0 is related to Orbit, SERAS and LOIS in terms of model development. The LASER model is expected to evolve further as it is applied to practical projects such as those mentioned above, and further modifications and extensions of LASER3.0 may be identified as version 3.1 and so on. 4 Laser Enhancement Project 2. Modelling approach and zoning The methodology that has been adopted in enhancing LASER can be summarised as follows: (a) It aims to address the weaknesses of LASER 2 as identified by the LASER Model Validation Project. (b) It is focused on updating those areas of the model which can significantly benefit from new land use and transport data which became available since the calibration of LASER 2. The data includes the SWS, LBS and SAR datasets from the population census, the AES and IDBR data for employment, the LATS and NTS data on travel choice, and the NAOMI and PLANET transport networks (see the Glossary for definitions of these various acronyms). The data was used not only to define a cross-sectional snapshot, but also, more importantly, to calibrate the patterns of residential location and modal choice behaviour of different socio-economic groups. (c) A modular structure has been developed. Whilst retaining a coherent theoretical framework, it enables some of the key elements of land use/transport simulation to be set up and used quickly for practical purposes within the tight time limits of practical studies. Its zoning structure is flexible enough to suit the varied requirements of applications in different geographical areas covered by the LASER study area. 2.1 Modelling approach The information flow within the LASER Model can be broadly described as being between four simulation procedures, the first two of which are considered as land use and the remaining two are transport: (a) Estimation of demand for employed persons, households, local services and floorspace; this is implemented through a generalised input-output model similar to a social accounting matrix (SAM). (b) Estimation of how such demand is distributed amongst the geographical locations within the study area. Journeys to work, school and services between geographical locations are a by-product of this procedure. Single level multinomial discrete choice models were calibrated on the Census and NTS data for their concentration parameters and residual disutilities (c) The journeys are attributed to different modes of transport that are available between each pair of locations, according to the modal choice behaviour of each socio-economic group. This is done by demand segment defined in terms of the SEGs, car availability and purpose of travel. Multi-level multinomial discrete choice models were calibrated on the London Area Transport Survey and National Travel Survey data for their concentration parameters and modal disutility functions. (d) The journeys on each mode are then assigned to the road and rail (including London Underground) networks, using a discrete-choice-model