Keywords: transport modelling, ilute, land use transport link

Keywords: transport modelling, spatial modelling, ilute

Keywords: transport modelling, spatial modelling, ilute

Lots of tiny details about simulation of market transactions. Includes some application to an Oregon model. Some discussion of fictional characters (auctioneer and aggregator) typical in microeconomic discussion of markets.

Keywords: urban economics, ilute

An economic market approach to urban system modelling is described, where all interactions are characterized as exchanges in a market. This leads to a natural partition of an integrated urban model into submodels based on the category of good or service being supplied or demanded, the type of agent making the demand or supply, and the time and place of interaction. Actors communicate through 6 defined operations on markets, decoupling the algorithms representing different behaviour. Agent based approaches to simulation are a natural extension of the market approach, allowing a transaction based simulation of heterogeneous spatial markets with individual agents making specific offers in specific places at specific times, and other agents accepting those offers at future specific times. Incorporating many existing modelling methods into such a framework requires a set of average prices by segmenting markets by commodity category, space and time, and wrapping the modules in interfaces that recast the inputs and ouputs into market operations. The paradigm is applied to two existing modelling frameworks: the Sacramento MEPLAN model and the Oregon statewide TLUMIP model.

Keywords: transport modelling, ilute

The network component of an integrated urban model called IMULATE is interfaced with the MOBILE5.C emissions models. IMULATE produces estimates of traffic flows and average speeds on each link in an urban road network using a user equilibrium assignment algorithm. This information is combined with speed-dependent emissions factors generated by MOBILE5.C to calculate estimates of the three types of emissions on a link-by-link basis. The combined models are implemented for the Hamilton, Ontario, Canada, metropolitan area. Simulations are conducted to illustrate the spatial patterns of emissions in the morning peak period and to demonstrate the impact of congestion on emissions estimates. The incorporation of detailed network performance information yields significant benefits in the estimation of regional automobile emissions.

Keywords: transport planning, transport modelling, ilute

Urban areas are very complex and heterogeneous in terms of their population composition and activity systems. The transit system, modal choices and service levels available to the population also varies considerably across space and time. These similarities and differences in choices and levels of explanatory variables facing individual tripmakers have to be explicitly considered in any study of transit behavior. The common practice has been to include user attributes, in addition to the system characteristics, in the modal utility functions to help capture differences in choice behavior across individuals. However, it could well be that the mode-choice behavior of a segment of the population is fundamentally different from other segments of the population. In view of this, some studies have applied segmentation schemes to help identify the subgroups of presumably different travel responses. Typically, such schemes have been based on stratification of the population by a single variable, chosen either based on a priori notions or one-way cross tabulations. This paper develops analytical procedure that simultaneously deals with level of service, socioeconomic and spatial factors to determine the relative role each plays in determining travel behavior. The procedure is applied to data from the Toronto region to illustrate its use.

Keywords: transport modelling, ilute

The prevailing practice in travel demand modelling is to estimate disaggregate models of mode choice with data from the most recent cross-sectional travel survey available on an urban area for forecasting purposes. Very often, however, most urban areas have available data from older cross-sectional surveys, which are often entirely ignored in the modelling effort. This paper explores the possibility of pooling data from two independent cross-sectional travel surveys on the same urban area for model estimation and forecasting by applying a model structure which allows for transfer-bias, referred to as the joint context estimation procedure. This procedure consists of joint, full information maximum likelihood estimation of a related set of logit choice models for the contexts which are based on the following two assumptions: (1) differences in model parameter values between contexts are expressible in terms of differences in the contexts' alternative-specific constants and overall scale of the contexts' utility functions; and (2) aside from these differences in alternative-specific constants and scales, model parameters are common across contexts. An empirical case study is presented, involving the use of two datasets, gathered 22 years apart (1964 and 1986) for the Greater Toronto Area (GTA), to estimate morning peak period work trip mode choice models. The estimated models are applied in prediction tests on the 1964, 1986 and a third independent data set, the 1991-data, also collected in the GTA. The performance of the joint context models is compared to that of an independent model, estimated on the 1986 data only. The results clearly demonstrate that joint context estimation dominates the independent 1986-model in predictive performance. The paper concludes by briefly discussing the possible roles, which joint context estimation might play in the development of improved transferability of disaggregate choice models.

Keywords: transport planning, transport modelling, ilute

Keywords: transport modelling, ilute, land use transport link

Keywords: travel behaviour, transport modelling, ilute

Keywords: computer science, geographic information systems, ilute

Keywords: transport modelling, ilute

Some interesting results from the CHASE survey. Shows that activity classification types (shopping, work, etc.) correlate very poorly with activity flexibility in time and space. Consequently, using an “average” flexibility for each activity type captures very little of the true flexibility of the activities.

Keywords: activity-based modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, canada, travel behaviour

Keywords: ilute, transport modelling, location choice

An empirical study of the temporal transferability properties of entropy-type trip-distribution models, applied within a fixed geographic region, is presented. Data for the study were drawn from three travel surveys conducted in 1964, 1986, and 1996 in the Toronto region. Very long transfer periods were examined, and a wide variety of model specifications were tested. These specifications ranged from the simple proportional flow model to an occupationally stratified, doubly constrained entropy model, for which spatial separation was measured by highway travel time. These models were estimated using data from 1964 and 1986. The estimated 1964 models were transferred to 1986 and 1996 to predict the distribution of travel. The 1986 models also were transferred to 1996 to predict the distribution of travel. Results showed that the travel-time parameter was not temporally stable. However, pragmatically, the transferred models were found to provide forecasts very comparable to those generated by models estimated in the respective application contexts. Improved model specification consistently resulted in improved precision of the forecasts obtained. In particular, stratification of the data by worker occupation category resulted in models with the best fit to estimation data, as well as forecasts. However, from a decision- oriented perspective, the improvement in precision obtained from additional complexity in specification did not warrant a recommendation for use of more complex models. Thus, the simple, doubly constrained entropy model with spatial separation measured by highway travel time appears satisfactory for use in practical modeling efforts.

Keywords: transport modelling, ilute, canada

Keywords: ilute, population synthesis

Keywords: ilute, population synthesis

Keywords: travel behaviour, transport modelling, ilute

Keywords: travel behaviour, transport modelling, ilute

Keywords: travel behaviour, transport modelling, ilute

Keywords: travel behaviour, transport modelling, ilute

Keywords: spatial modelling, ilute, canada

Keywords: spatial modelling, ilute, canada, urban planning

Keywords: spatial modelling, ilute, urban planning, land use transport link

Proximity to transportation infrastructure (highways and public transit) influences residential real estate values. Housing values also are influenced by propinquity to a shopping facility or a recreational amenity. Spatial autoregressive (SAR) models were used to estimate the impact of locational elements on the price of residential properties sold during 1995 in the Greater Toronto Area. A large data set consisting of 27,400 freehold sales was used in the study. Moran's I was estimated to determine the effects of spatial autocorrelation that existed in housing values. SAR models, using a combination of locational influences, neighborhood characteristics, and structural attributes, explained 83% variance in housing values. Using the “comparable sales approach,” a spatiotemporal lag variable was estimated for every property in the database. This research discovered that SAR models offered a better fit than nonspatial models. This study also discovered that in the presence of other explanatory variables, locational and transportation factors were not strong determinants of housing values. On the other hand, the number of washrooms and the average household income in a neighborhood were found to be significant determinants of housing values. Stepwise regression techniques were used to determine reduced spatial hedonic models.

Keywords: ilute, canada, urban planning, land use transport link

Keywords: ilute, transport modelling, travel behaviour

Keywords: transport modelling, ilute

Keywords: ilute, transport modelling

This paper describes the development and testing of a microsimulation of the evolution of individual ”business establishments” (BEs) in an economy. The work is part of a larger program of research and development of a model of all the transportation and land development processes in an entire spatial economic system. The simulation uses comparatively simple, yet behavioural, rules and probabilistic models, using a Monte Carlo process to simulate behaviour from the probabilistic models. A BE is described primarily by its business transactions - its purchases and sales of standard commodity categories, called its “consumption function” and “production function” respectively. Make and Use tables from traditional input-output models are used to determine these relationships for a particular industry, and individual BEs randomly vary around the industry average. Labour, floorspace and final demand are included as commodities, to bind the BEs to a given built form in a spatial system and to the patterns of population. Thus a BE is described in terms of how big it is, and its “technical coefficients” describing what it purchases and sells.

The market for each commodity type is spatially disaggregated, and BEs in a given location can sell or purchase their commodities in a variety of different “exchange zones” that they are willing to ship goods or services from or to. Prices at exchange zones are adjusted over time so that, if the system is allowed to reach equilibrium, the market for each commodity in each exchange will be cleared. The BE's market choice model is used to develop measures of the attractiveness of selling or purchasing commodities when located in a zone. These measures of commodity attractiveness are used with the production function and consumption function to determine how attractive a location is for a given BE and how well it is performing. A BE's growth (positive and negative) and its probability of bankruptcy (death) are based on the measure of location attractiveness. Relocation pressures are based on the measure of location attractiveness, as well as a composite measure of the attractiveness of all other zones in the system and the (fixed) attractiveness of leaving the model region entirely. Relocating BEs vacate floorspace in a particular physical location (a “grid cell”) and then, if necessary, acquire new floorspace in a grid cell in a different zone. As a successful BE grows it is increasingly likely to split into two separate BEs, either as a duplication of function into another location, or a separation of business functions into separate locations. In addition, entrepreneurial business ideas are set up as “Proto BEs”, which are business ideas that are being evaluated in any one year. A “Proto BE” that is in an attractive location in one year is likely to become an actual BE in the next year. Within each zone, the land is represented as “grid cells”, which are finite quantities of land with a particular type and quantity of floorspace and a particular building age. The prices for each floorspace type in each zone, along with the age, type and quantity of floorspace in each grid cell, are used to calculate the probability that the land owner will choose to undertake development, redevelopment, renovation or demolition in the grid cell. The test system is represented using a 10x10 system of zones and a network of transport connecting the zones with reasonable travel times and costs. This system is used to test the role of the various parameters, to determine reasonable values for the parameters, how the model behaves when parameter values are unreasonable, and how each parameter influences the model system. A set of “policy input” scenarios are also developed, to show how the modelling system can be used to test the policy response. These include decreased development costs, increased travel costs and changed land-use zoning regulations.

Keywords: ilute, spatial modelling

Keywords: transport modelling, ilute

The primary goal of activity-based models is a fundamental examination of the behavioral process that results in revealed travel behavior. To reveal this process, a new computer program, iCHASE, has been developed to collect data for a study of the determinants of travel and activity behavior in households. These data are inherently dynamic, since respondents record planned activity schedules and then update these schedules on a daily basis, fully defined in time and space. The resultant data will facilitate the identification of fundamental inter-relationships among a comprehensive range of revealed travel and activity participation variables, leading toward the identification of the critical variables, relationships and rules that govern that behavior. It is believed that an Internet-based travel survey, particularly one as rich in resultant content as iCHASE, will significantly reduce data collection costs, improve data quality and quantity and allow for continuous data collection.

Keywords: transport modelling, ilute

Recent developments in the area of dynamic household activity scheduling require better understanding of the behavioural aspects of scheduling processes within households, and, in particular, formation and modification of the provisional schedule, conflict resolution, and rescheduling processes. The goal of this paper is to identify and examine scheduling processes within households using data collected in Quebec City using the Computerized Household Activity Scheduling Elicitor (CHASE) survey software. CHASE addresses the problems of detailed data collection not only concerning activities and travel per se, but also scheduling behaviour processes themselves, including dynamic modifications to the schedule during its execution phase. Univariate analysis performed on the CHASE data provides insights and correlations between household characteristics and the nature of these processes but also questions the activity scheduling approach based on generic activity type classification rules.

Keywords: transport modelling, ilute, travel behaviour

Keywords: ilute, transport modelling, travel behaviour

This paper provides a quantitative analysis and comparison between the recent Toronto Activity Panel Survey CHASE (Computerized Household Activity Scheduling Elicitor) dataset and a previously collected Quebec City CHASE dataset with the focus on household agenda formation.

The CHASE datasets were analyzed in the context of a newly developed event-driven time-series based activity scheduling framework that explicitly incorporates individuals' agenda formation. The modelling framework, based on McTaggart's concept of time, has two levels of agenda abstraction: conceptual and perceptual, where the second level of abstraction includes provisional sequences of activity episodes. CHASE has been designed to provide detailed observation of scheduling processes and agenda formation. In particular it allows one to trace activity schedule evolution from the planning phase, through modification phases to the execution phase. An original computer algorithm has been applied to the datasets to allow the analyst to visualize the development of provisional activity sequences.

Keywords: transport modelling, ilute, canada, travel behaviour

The time dimension in decision-making and activity scheduling models in both conceptual and operational applications is a critical issue. A crude conceptualization of time in current models creates a number of problems with representing dynamic decision-making processes and limits the potential of existing models. Event-Driven Time-Series Based Dynamic Model of Decision Making Processes is a proposition of a modeling framework that attempts to simulate the natural way of decision-making and scheduling behaviour which transforms agent's ideas from their conceptual phase through a provisional schedule to eventually executed activity patterns. It is based on concepts of time in philosophy and science of social behaviour and psychology. The Event-Driven Time-Series Based Dynamic Model links short-term scheduling with long-term planning and lifetime decision-making. This provides a natural link with car ownership or land use models and also provides for a dynamic interface with microsimulation models of network performance sensitive to short-term fluctuations of traffic condition. The model explicitly utilizes conceptual and perceptual time-spaces and exploits non-linearity and multidimensionality of decision-making time-space. The decision-making agents explicitly recognize a time horizon and their decision-making behaviour is driven by events.

Keywords: transport modelling, ilute, travel behaviour

A good overview of the current status of the ILUTE project.

Keywords: ilute, transport modelling

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: travel behaviour, transport modelling, ilute

Keywords: ilute, transport modelling, urban planning

Keywords: transport modelling, ilute, land use transport link

This paper presents a status report concerning on-going research and development work by a team of Canadian researchers to develop a microsimulation, agent-based, integrated model of urban land use and transportation. It describes in some detail the overall design and current status of the ILUTE (Integrated Land Use, Transportation, Environment) modelling system under development. The overall purpose of ILUTE is to simulate the evolution of an entire urban region over an extended period of time. Such a model is intended to replace conventional, aggregate, static models for the analysis of a broad range of transportation, housing and other urban policies. Agents being simulated in the model include individuals, households and establishments. The model operates on a “100% sample” (i.e., the entire population) of agents which, in the base case, are synthesized from more aggregate data such as census tables and which are then evolved over time by the model. A range of modelling methods are employed within the modelling system to represent individual agents' behaviours, including simple state transition models, random utility choice models, rule-based “computational process” models, and hybrids of these approaches. A major emphasis within ILUTE is the development of microsimulation models of market demand-supply interactions, particularly within the residential and commercial real estate markets. In addition, travel demand is modelled explicitly as the outcome of a combination of household and individual decisions concerning the participation in out-of-home activities over the course of a day. Spatial entities in the model include buildings, residential dwelling units and commercial floorspace, as well as aggregate “spatial containers” such as traffic zones, census tracts or grid cells.

Good references: ConLaw02, VelKapTim00, VosPetDon02.

Their discussion of spatial representation is interesting, and echos (somewhat) my own thoughts on the subject. They have two sections: one on residential representation and one on representations for firms. I'm curious to see how far they've come in the last few months.

They discuss real estate markets, with zonal average prices. Offers can have individual prices, though, overriding zonal averages. It seems that this idea would mesh better with building-based spatial representation-grid based representation makes it hard to store data like “sale price” or compute zonal averages.

I'm a bit baffled by their commercial development model. The grid-based approach they used seems to be based on cellular automata, using logit models for state transitions. But they don't consider adjacency information, which seems like it would be essential for firms-who wants floorspace divided into a random patchwork? Can you really just rearrange floorspace as needed?

Their closing paragraphs are encouraging: they really don't want zones, anywhere.

Keywords: transport modelling, ilute, spatial modelling

detailed annotation

Keywords: transport modelling, ilute, transit, land use transport link

Keywords: transport modelling, ilute, transit, land use transport link

The case is presented for a new, coordinated research and development (R&D) program designed to improve significantly the operational state of practice in integrated urban modeling. First, the authors' view of an “ideal” integrated urban modeling system is described. If developed, this modeling system should be capable of incorporating the best possible understanding of transportation and land use interactions and of addressing planning and analysis needs. Also discussed briefly are current operational modeling capabilities as related to the proposed ideal model. Finally, a multiyear R&D program that was designed to move current practice significantly toward the operationalization of the ideal model is detailed.

Keywords: transport modelling, ilute, land use transport link, transit

Keywords: transport modelling, ilute

Keywords: transport modelling, ilute, canada, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Interesting and useful.

I find one assumption dubious: the decision to use a car for one part of a chain requires its use for the rest of the chain. In a city like Toronto where downtown parking is very inconvenient, I might drive downtown, park, and then do a long chain of trips on foot before returning to the car.

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, canada, urban planning, transport planning

Keywords: ilute, transport modelling, travel behaviour

Keywords: transport modelling, ilute

Keywords: transport modelling, ilute

Keywords: transport modelling, ilute

Keywords: transport modelling, ilute

Microsimulation modeling is an emerging approach to activity-based travel forecasting. Household automobile-ownership models are being included in microsimulation travel-demand models more. Implicitly, vehicle price is an important attribute of vehicles in all automobile-ownership models. In order to update prices at each point of time within the simulation, a modeling tool is required to estimate the price of each vehicle at any time. This paper develops a hedonic price model to estimate the expected price of vehicles to be used in a comprehensive urban-transportation modeling system. In this study, the use of a linear hedonic price model was investigated in terms of its application to the market price of automobiles.

Seems pretty reasonable. It's a little surprising that fuel economy makes a car less attractive, but I suppose that's typical of the 1990s vehicle market. Perhaps a repeat of the study today would show different results. (The price of gas was not a study variable, and didn't vary much over the period when the data was collected anyways.)

Keywords: activity-based modelling, ilute, travel behaviour, vehicle ownership

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute

Not very useful for my purposes, although I'm sure anyone interested in emissions analysis might appreciate it. It's curious that gasoline prices aren't considered a relevant variable.

Keywords: transport modelling, ilute

Keywords: ilute, transport modelling

Keywords: ilute, transportation modelling

Keywords: ilute, transport modelling

Keywords: transport modelling, ilute

Keywords: transport modelling, ilute, canada

Keywords: travel behaviour, transport modelling, ilute

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, canada

Keywords: transport modelling, ilute, travel behaviour

Keywords: transport modelling, ilute, travel behaviour

Recent work in the area of comprehensive transportation modeling systems in a microsimulation framework, more specifically auto ownership modeling, has recognized the need for increased experimentation with dynamic models. Implicitly, dynamic models require longitudinal data. A Toronto area car ownership study was conducted to design and administer a longitudinal survey to fulfill the data requirements for such a dynamic model, to validate the survey results, and to conduct preliminary analysis on those results. An in-depth retrospective telephone survey was conducted with the help of a computer aid in Toronto, Canada. Simple univariate analyses were conducted on the data to determine the relationship between characteristics of the household and the occurrence of vehicle transactions, the choice of vehicle type, the duration a vehicle is held, and the degree of consumer loyalty to different types of vehicles.

I read this after Mohammadian's later papers. It looks like they did collect home/employer locations during the surveys-why didn't they use this information?

Keywords: transport modelling, ilute, canada

Keywords: transport modelling, ilute

Keywords: transport modelling, ilute

Keywords: transport modelling, ilute

This paper will explore disaggregate approaches to modeling urban systems, organizing recent research, approaches, techniques and assumptions. As we know, the advantage of disaggregate approaches are that they begin with the individual, the finest resolution, enabling aggregation without losing valuable information. There is no single modeling technique that can provide a useful simulation of individual behaviour within the urban system. Instead, a variety of approaches must be integrated within a macro model. Each has differing assumptions, strengths and weaknesses. The paper will establish the players, decisions made and outcomes of modeling urban systems. Given these categories, a review of current literature demonstrates the emerging approaches for different aspects of the urban system model, identifies strengths and weaknesses and examines underlying assumptions and data collection techniques.

Keywords: transport modelling, ilute

Keywords: transport planning, urban planning, ilute, canada, urban form, land use transport link

Keywords: computer science, geographic information systems, ilute

He makes some very valid criticisms of integrated transportation/land use models. He has four things in particular that he'd like to see done: induction of principles of spatial behaviour; development of context and domain-specific behavioural models, where he complains about the use of multinomial logit models for residential location decisions, despite the fact that most households have very limited information and housing literature gives better models; development of truly integrated models, instead of cobbling together existing models and all of their assumptions; modelling of spatial planning and its effects on urban form, including P3s.

Keywords: transport modelling, ilute, land use transport link