Pergamon
Comput., Environ. and Urban Systems,Vol. 20, No. 4/5, pp. 327-338, 1996 © 1997 ElsevierScienceLtd All fights reserved. Printed in Great Britain 0198-9715/96 $17.00 + 0.00
PII: S0198-9715(97)00009-4
A DECISION SUPPORT SYSTEM FOR INTEGRATING LAND USE, TRANSPORT AND ENVIRONMENTAL PLANNING IN DEVELOPING METROPOLISES Kazuaki Miyamoto, * Rungsun Udomsri, t Sathindra Sathyaprasad ~ and Fuhu Ren § •Department of Civil Engineering, Tohoku University, Aoba, Aoba-ku, Sendai, 980-77, Japan t Department of Civil Engineering, Chiang Mai University, Chiang Mai, 50200, Thailand tDepartment of Civil Engineering, University of Peradeniya, Peradeniya, Sri Lanka ~United Nations Center for Regional Development, Nagono, Nakamura-ku, Nagoya, 450, Japan ABSTRACT. In most metropolitan areas in Southeast Asia which are rapidly growing, many kinds of urban problems related to land use, transport and the environment are emerging. To improve urban management in the region, a top priority is therefore to strengthen the capacity for planning and policy implementation through better coordination among related agencies. This would be aided by an effective analysis tool for planning with which related agencies could substantially discuss policies and their implementing measures. This paper presents such an analysis system which is a new approach for the integrated planning of land use, transport and the environment in a developing metropolis. It stresses operational and conceptual simplicity as well as flexibility for applicability to developing countries. A prototype system, with Bangkok as the case study area, has been developed within the MS-Windows environment, and it employs an extended version of the Random Utility~Rent-Bidding Analysis ( R URBAN) model for activity allocation and transport calculation. The system can also forecast environmental results of changes in land use and transport conditions. © 1997 Elsevier Science Ltd
INTRODUCTION Since urban change within metropolitan areas in developing countries is so rapid and dramatic, it can be said that integration of land use planning and transport planning, and taking the environment into consideration, is much more important and necessary than it 327
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is in developed metropolises. However, very few developing countries have a planning body which covers all three elements. They have neither the required institutional set-up nor the technological support. In addition, the difficulty in financing costly projects is probably the most important cause for the delay in implementation, along with lack of technology to evaluate costs and benefits. A decision support system, therefore, which covers land use, transport and the environment can not only contribute to integrated planning but also accelerate an implementation program by clarifying benefit and social cost distributions. This paper aims to build such a decision support system using a personal computer. The system may become a strong tool for establishing a forum in which agencies related to land use, transport and the environment can discuss policies, their implementing measures, and the implementation programs needed in view of their interactions.
INSTITUTIONAL AND TECHNICAL SUPPORT Institutional problems among agencies concerning land use, transport and the environment are some of the most difficult problems to solve. Without good coordination between agencies, integrated planning and implementation cannot be conducted (Miyamoto & Udomsri, 1994). It is therefore necessary to provide a forum for concerned agencies where they can discuss various policies as well as their implementing measures. The analysis tools described in the following part of this paper are expected to work for such a purpose. Without this comprehensive system, it will be nearly impossible for agencies to attain mutual consensus in order to adopt an integrated strategy. Another important issue in the realization of plans, is how to adopt appropriate measures or instruments that would facilitate the implementation of the plans. In achieving this, policy measures should be coordinated as an integrated set of policy elements. Such policy elements should be selected with a view to the interaction between land use, transport and the environment as well as among the agencies. In this study policy elements are classified into five categories--regulation, taxation/pricing, investment, operation and education, and an actual set of policy measures within integrated planning would be a combination of such elements. The concept of integrated policy measures in this study is similar to the integrated strategies approach (May, 1991) and/or the management approach in transport planning, but it also covers land use and the environment explicitly. Also, for the purpose of quantitative evaluation, analytical models need to be capable of representing the complex interaction between transport and land use, and also provide information for evaluation. Moreover, quantitative analyses of the impacts of selected policy measures are made effectively, and understandably, by the decision support system. In other words, any user-friendly computer system, with understandable graphics, brings a variety of benefits other than those generally understood. There will be two kinds of interactions: between computer and planner, and between computer and model/system builder. In the former case, the system will quickly provide the planner with various information in an understandable manner. This function supports decision making in planning through a forum for integrated planning, as described above. On the other hand, it will become a good educational tool for planners through its simulations of various cases. This kind of
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learning will make the planner propose a better plan which would have been possible without the learning process. Such training also reduces the number of alternatives. In the case of interaction between model/system builder and computer, the system helps the builder to work smoothly for further developments. Since land use, transport and the environment are fundamentally spatial information, the system can assist the model/ system builder in the calibration and enhancement of each model. Many kinds of land use, transport and their integrated models have been developed to forecast change for various purposes, and some of them are applicable to forecasting environmental changes (Webster, Bly, & PauUey, 1989; Wegener, 1994). However, most of them have little compatibility with other models. Each model development aims to build its own customized simulation model, it does not utilize existing program modules and, in general, there has not been much standardization in simulation programs of land use, transport and environment models. Since existing program modules have various mechanisms for data input and output, they cannot be used as standard parts of a large simulation system. Therefore, whenever we prepare an analysis system for integrated planning and implementation, our system should consist of modules for land use, transport and the environment. But, it would take a long time, and be costly, to develop all the simulation models only by ourselves. Hence, it is as important to establish a standard in order to provide an existing stock of program modules with an interface, by which the modules can be systematically connected to the simulation system. We should, therefore, set up a general framework for an analysis system which allows itself to easily incorporate and replace modules for land use, transport and environment across any relevant sector of a metropolis. Hence, we intend to provide a general framework for an integrated analysis system of land use, transport and the environment. The basic aim is to make the development of the system feasible even within developing countries. The principles for the system development can be summarized as follows: (1) (2) (3) (4) (5) (6)
to make a prototype system that can be easily introduced almost everywhere; to make the system able to deal with integrated policy measures; to make the system user-friendly; to make the system useful also for the development of the system itself; to make the system flexible for existing models; and not to stick to our own models but to provide them as alternative models.
AN INTEGRATED, ENVIRONMENTALLY SENSITIVE MODEL OF LAND USE AND TRANSPORT The main part of our analysis system is an integrated land use and transport model. In this study, a land use model named Random Utility/Rent Bidding Analysis (RURBAN) (Miyamoto, Naomi, Kuwata, & Yokozawa, 1992) has been improved to represent transport more explicitly, while ensuring consistency between land use and transport. The improved model can be operated not only by directly integrating land use and transport but also by separating them. Figure 1 shows the structure of the integrated model of land
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FIGURE 1. The structure of an integrated land use, transport and the environmmt model. (Source: Miyamoto & Udomsd, 1996.)
use, transport and the environment. RURBAN can estimate land use and land price (or renQ, within a metropolis, by grid, and whenever transport and other locational conditions such as land use zoning are given. RURBAN employs the Aggregate Logit model structure as described in the next section.
Modelling Location Behavior, Transport Choice and Environmental Impacts In RURBAN, the land market is grasped from the viewpoints of both locators and sites. If a locater chooses a certain site, it implies that the site must give the locater the highest utility from amongst all alternative sites. On the other hand, it also explains that the locater must bid the highest rent among all alternative locators at the site. At the level of aggregated locater groups and zones, the market can also be so explained, although probabilistic consideration should be introduced to represent the coexistence of a number of locators in a zone where there are a number of sites. Locators belonging to a group are distributed in zones in proportion to the probabilities with which the zones provide that group with the highest utility. The share of area by a locater group in a zone is also proportional to the probabilities that the corresponding locater group bids the highest rent at that zone. Such probabilities are obtained by Legit models in RURBAN. In this modelling, "the rents in all zones" and "the levels of utility of all locater groups" are indispensable. Choices in location and trip are viewed as an outcome of a probabilistic choice process. Any choice process is simply described by four levels of a choice hierarchy in the dc~-'isionmaking chain, starting from location choice and destination choice at the land use level,
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and moving to mode choice and route choice at the transport level (Miyamoto & Udomsri, 1996). Finally, once land use and transport conditions are predicted, environmental impacts are estimated as externalities of land use and transport. Transport related environmental items, such as air quality, are defined as functions of link traffic characteristics and the service levels. Land use related environmental items, such as solid waste, are defined taking into consideration the activity levels, locator compositions, and the land cover of the zones. The present version of the system is equipped only with a model which estimates the volume of solid waste by grid. The model takes into consideration the difference by grid in emission rate of solid waste per capita which is caused by the activity level in each zone. Land price, an output of the land use simulation, is considered as representing the land use activity level. Other environment modules are being installed into the system.
Arfhitecture of the Integrated Model As shown in Figure 1, land use distribution (nls: number of locators belonging to Group I in zone S) is actually the output of the land use model and also the input, as the attractiveness of a destination, for the transport model. In the land use model (RURBAN), iteration is needed to get convergence, and in the transport model transport service level (Vc: velocity on link c), as output after convergence, is actually the input into the land use model. In addition, the entire model for integrated land use, transport and the environment requires more iterations for convergence. Also, iteration of the whole system should start from the equilibrium situation, that is, the point of convergence, of the previous period.
SYSTEM STRUCTURE AND FUNCTIONS Our integrated analysis system has been developed within the Microsoft Windows 3.1 environment. This was selected because: (1) (2) (3) (4)
application programs can be shared with a standard input/output interface; it is one of the most popular operating systems; it can be operated on personal computers which are normally available in any place; and the system has high potential for further development.
This environment also makes use of features like Graphical User Interface (GUI), Dynamic Data Exchange (DDE) facilities, the use of icons, drop-down menus and dialog boxes. Moreover, direct screen interaction through a mouse provides a more user-friendly interface for both editing input information and output presentation. Note that the Dynamic Data Exchange facility provides for automatic data transfer between the different modules used in the development of the system. This kind of user-friendly interface, plus automatic data exchange facility, are very important in achieving the objective of integrated analysis.
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Our system's Graphical User Interface has been designed under the MS Visual Basic environment, since Visual Basic provides an easier and a more interactive way of designing the user interface than does the Windows Software Development Kit (SDK) or C programming. It also saves considerable time in system development that is usually spent designing a user interface. Figure 2 shows the conceptual framework of the analysis system. Integrated policy input, output presentation, and the original database are linked to the Graphical User Interface. The simulation models for land use, transport and the environment are then connected to a common simulation data set through the Dynamic Data Exchange facility. However, since data formats of the individual simulation models are not necessarily the same as those of the common simulation data set, the simulation models are linked to the simulation data set through data converters.
Features The simulation data set is one of the most important parts of the system and it contains all land use, transport and the environmental data for the metropolis at desired levels of analysis. In other words, it represents a simulated world for the metropolis. As the simulation data set is linked to the simulation models through the Dynamic Data Exchange facility, each year's data is automatically updated as a result of the simulation. The analysis procedure within the system is as follows:
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project identification, specification and retrieval of the base map and databases; specification of evaluation criteria, selection of analysis models and definition of simulation controls; input of policy information, interactively, through the Graphic User Interface; simulation; and retrieval of simulation output and output presentation.
Note that the Decision Support System is developed so that, with minimum revision, it can be used in the analysis of a different metropolis, or even handle different metropolises at the same time. This is achieved simply by identifying the project at the beginning, through a "Load Project" dialog box. This retrieves the relevant base map and other graphical and database information. Such information includes the zoning system, the existing transport network, the land use transport and the environmental situation of the base year. Such information is pre-set, although it is accessible to the user for editing. Also, the base map can be a scanned topographical map or a remote-sensed image of the study area, and any base map is stored as a raster bitmap for MS-Windows. It provides the visual background for displaying a zoning system, a transport network, land use and environmental information, and it acts as an interactive policy information input, along with simulated output. In addition, transport networks are stored as vector files. Different existing networks such as highways and railways are displayed on the base map, thereby providing the user with a visual background and a guide for the editing and extending the transport infrastructure. Such information also includes link/node characteristics. Moreover, land use and the environmental situations are stored both as raster bitmaps and as databases developed under the MS-Access database management system. Simulated outputs of land use, as well as environmental situations, are also stored in separate databases for comparison. It also needs to be remembered that our integrated system has the facility to use different models for land use, transport or environment forecasting. At this step the user is given flexibility to select simulation models and to run the simulation models either independently or as an integrated model. It also enables the user to control parameters, such as the simulation period, the time lead or lag and the number of iterations, using menus and dialog boxes. Note that policy information may be entered through menu-driven dialog boxes as well as interactively using graphical images. Selection of policy alternatives, and the input of policy information which are global and numeric in nature, such as fuel taxation, are entered through menu-driven dialog boxes. Policies which are spatial in nature, such as land use zoning or infrastructure development, are easily entered through the editor. The latter has the facility to erase errors during input and to save the final information in the original database, thereby enabling graphical data updates. Running a Simulation Once the project definition and simulation controls are set, and once the policy information has been input, simulation can be activated through menu-driven commands. When the simulation is activated, it is carded out according to the project definition and the simulation control parameters established previously. This uses the analysis models
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assigned. Run-time and on-screen messages inform the user of the status of simulation. At the end of the simulation, results of the simulation are stored in a separate output database, which can be accessed through the graphical user interface. Note that simulation output can be displayed on-screen in different formats. The graphical user interface enables the user to make With-Project/Without-Project comparisons or to view the change itself. The output information includes land use, transport and the environmental situations of different zones for "With-Project" and "Without-Project" conditions, or due to the implementation of a particular set of policy measures. The user can view the different output information in some desired format just by clicking on a multi-level menu system. Programs of all simulation models are written in FORTRAN, and the rest of the system, mostly graphic presentation and simulation control, is written in Visual Basic, except where existing software packages are used. Digital files for spatial and vector information are normally difficult to create. However, this system provides a facility for drawing details onto a familiar base map, with convenient mouse-clicks using a simple toolbox. For example, a highway link can be input just by selecting "Highway" from the toolbox and clicking along the position of the highway on the map. Highway interchanges can be input just by selecting "Interchange" from the toolbox and clicking on the desired interchange positions. An input feature can be also deleted in the same way. Hence, instead of digitizing a road network map, network data can be input and saved directly. Note that scroll bars are provided to scroll the image wherever the screen cannot display the full base map of the study area. Databases for the land use, transport or environment information can be easily edited, for a particular zone, simply by clicking on the zone, selecting a database item and editing in the dialog box, and data query is one of the very important facilities available in the system. To query different database items linked to a particular zone, a user can either query the tabular information from the map or vice versa. In the first type of query a user can view database items relevant to a particular zone by clicking on the zone and then selecting the group of database items from the "Database" menu. Such items can either be viewed as "With-Project", "Without-Project" or "Comparison", for example, one may need to find the "solid waste generation" in a zone. In the second type of query, a user can view the zones with a particular database item falling within some given range. For example, one may need to know the zones "with ambient NO2 levels exceeding the WHO recommended values". When the user makes such a query through a dialog box, the corresponding zones are shadowed on the base map. This two-way data query is very useful in analyzing a situation, as the user can obtain the required information directly. Finally, the system provides an on-line help facility, with explanations of different menu commands and "How to do" facilities.
PILOT SYSTEMS RURBAN/Sapporo for Windows is one of the most advanced versions. It is a modified version of RURBAN/Sapporo which was completed to operate the RURBAN land use model within the MS-DOS environment (Miyamoto et al., 1992). The integrated model of
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land use transport and the efl,dronment is also being installed in a pilot system whose study area is Bangkok.
Model Calibration for Bangkok The study area covers the Bangkok Metropolitan Administration (BMA) area. The total area of BMA is about 1568 km 2 which has been administratively divided into 35 districts. The population of the study area was about 5.4 and 5.6 millions in 1985 and 1990, respectively. The definition of the study area zoning system stemmed partly from the source of data being used, mainly from the various studies during 1985 and 1990 (BMA, 1991; NESDB, 1991). In order to make the system building begin promptly, simplified information on land use and the transport network, in coarse aggregate units, is applied to represent the metropolis. The zoning system is defined corresponding to the administrative district boundaries within which demographic and socioeconomic data are available. Area and land use attributes are aggregated into 30 larger zones. Also, the transport network is represented in the form of a simplified aggregate network. For land use analysis, locators are modelled into four locator groups: residential, commercial, industrial and agricultural. The agricultural group represents non-urban land uses as well as vacant land. The total number of residential locators are estimated from the population and the number of households. Commercial and industrial locator groups are extracted from the number of companies and factories that are registered in the study area. Also, the number of agricultural locators is estimated from the ratio of primary employment to total employment. For simplification of analysis, the utility function and bid-rent function are assumed to be functions only of the transport condition and the composite land use condition. Travel time to the Central Business District (CBD), which is common for all locator groups, represents the transport condition in each zone. Also, the composite land use condition of each locator group in a zone is given according to observed land use distribution within that zone.
Preliminary Test Results The results of the calibration phase of the model-building exercise can also be considered as a measure of the base year performance of the model. The land use parameters are estimated by rent-bidding analysis. The validity of the estimated parameters for the utility function is confirmed by the goodness-of-fit of the estimated distribution of locators to the observed distribution. A p 2 value of 0.28 indicates an acceptable level for parameter estimation in this study. The outputs of the R U R B A N model are the number of locators in each zone for each locator group, average land price in each zone, average utility for each locator group, and the area in each zone which is occupied by each locator group. The population in each zone could be estimated from the number of residential locators. The trip end estimation is based on numbers of households, and commercial and industrial locators, by zone. These data can be obtained from the output of the R U R B A N land use model as discussed in the previous section. The base year analysis procedure provides estimates of trip generations and attractions, by purpose. Such estimates are
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checked against the available data source. The performance and calibration of this particular submodel have been measured and achieved by maximizing the value of r z for the data, by zone. We report that the prediction test has actually been satisfied with a good correlation coefficient. Note that one of the most important functions of the analysis system is presentation of output information in an understandable and clear form. Hence the pilot system for Bangkok is designed to have functions for selecting, organizing, and displaying information as well as for providing quantities of model outputs using graphical presentation methods. Figures 3 and 4 show examples of the resulting screen display.
CONCLUDING REMARKS In this paper, a decision support system for integrated planning of land use, transport and the environment has been described. The system is being applied not only to Bangkok but also to Sapporo in Japan. The conceptual design of this system has been completed and a pilot system based on the concept has also been built, as described in this paper. Since the system covers wider aspects of a metropolis, it is being developed to incorporate more functions.
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ACKNOWLEDGEMENTS--The authors would like to express their sincere appreciation to Professor Hideki Kaji, Director of the United Nations Center for Regional Development, for his invaluable suggestions and support in the development of the decision support system.
REFERENCES Bangkok Metropolitan Administration (BMA) (1991). Bangkok transportplanning unit (BTPU): Phase I. May, A. D. (1991). Integrated transport strategy: A new approach to urban transport policy formulation in U.K. Transport Reviews, 11(3), 223-247. Miyamoto, K., Noami, T., Kuwata, Y., & Yokozawa, K. (1992). An Evaluation Method of Transport Projects with the aid of RLIRBAN (Random Utility/Rent-Bidding Analysis) Model, Selected Proceedings of the Sixth World Conference on Transport Research, 1, 55-66. Miyamoto, K., & Udomsri, R. (1994). Present situations and issues of planning and implementation regarding land use and transport in developing countries. Journal of Infrastructure Planning and Management, JSCE, No.482]IV-22, 87-97. Miyamoto, K., & Udomsri, R. (1996). An analysis system for integrated policy measures regarding land use, transport and the environment in a metropolis. In Y. Hayashi, & J. Roy (Eds.), Transport. land use and the environment (pp. 259-280). Norwell: Kluwer.
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National Economic and Social Development Board (NESDB) (1991). The seventh plan urban and regional transport (SPURT), Bangkok. Webster, F. V., Bly, P. H., & Paulley, N. J. (1988). Urban land use and transport interaction--Report of the international study group on land use/transport interaction (ISGLUTI), Avebury. Wegener, M. (1994). Operational urban models.. Journal of the American Planning Association, 60(1), 17-29.