Paul Waddell

Integrated Land Use and Transportation Planning and Modelling: Addressing Challenges in Research and Practice

Abstract Academic research in integrated land use and transportation modelling is on the rise, in no small part due to growing interest from public agencies that need to improve their capacity to respond to complex policy questions arising in the context of transportation, land use and environmental planning. But the process of taking models developed in an academic research setting, where theoretical validity and the advancement of methodology receive high priority, and moving them into public agency settings in which priorities such as reliability, ease of use and staff capacity to explain to stakeholders what the models are doing, and why, create predictable gaps in understanding and can undermine a project. In this paper, we develop lessons from the experiences of multiple planning agencies in applying UrbanSim in their operational agency settings and integrating it with their transport model systems. In contexts as varied as Detroit, Honolulu, Houston, Phoenix, Seattle and San Francisco, we find that there are common elements to the tensions of appropriating a model system for their own use. We assess how the evolution in the design of the model system has responded to policy and technical challenges presented by this domain, and propose directions for further development.

Interactive design of urban spaces using geometrical and behavioral modeling

The main contribution of our work is in closing the loop between behavioral and geometrical modeling of cities. Editing of urban design variables is performed intuitively and visually using a graphical user interface. Any design variable can be constrained or changed. The design process uses an iterative dynamical system for reaching equilibrium: a state where the demands of behavioral modeling match those of geometrical modeling. 3D models are generated in a few seconds and conform to plausible urban behavior and urban geometry. Our framework includes an interactive agent-based behavioral modeling system as well as adaptive geometry generation algorithms. We demonstrate interactive and incremental design and editing for synthetic urban spaces spanning over 200 square kilometers.

Inverse design of urban procedural models

We propose a framework that enables adding intuitive high level control to an existing urban procedural model. In particular, we provide a mechanism to interactively edit urban models, a task which is important to stakeholders in gaming, urban planning, mapping, and navigation services. Procedural modeling allows a quick creation of large complex 3D models, but controlling the output is a well-known open problem. Thus, while forward procedural modeling has thrived, in this paper we add to the arsenal an inverse modeling tool. Users, unaware of the rules of the underlying urban procedural model, can alternatively specify arbitrary target indicators to control the modeling process. The system itself will discover how to alter the parameters of the urban procedural model so as to produce the desired 3D output. We label this process inverse design.

The Effect of Impact Fees on the Price of New Single-family Housing

This paper provides new evidence on the effects of impact fees on housing prices, using an inventory of single-family housing sale transactions in the 38 cities and towns within King County, Washington, for the period 1991-2000. Although the effect of impact fees on housing prices has been examined previously, earlier studies have been limited by methodological deficiencies. This paper examines the effect of impact fees on new housing and their differential effect on housing price based on the quality of housing, and finds that the effect of impact fees on the price of new housing is quite significant and elastic, raising new home prices by about 166 per cent of the amount of the fee. The increase is 358 per cent for the higher-quality homes and is statistically insignificant for the lower-quality homes.

Integrated Land Use-Transport Model System with Dynamic Time-Dependent Activity-Travel Microsimulation

The development of integrated land use–transport model systems has long been of interest because of the complex interrelationships between land use, transport demand, and network supply. This paper describes the design and prototype implementation of an integrated model system that involves the microsimulation of location choices in the land use domain, activity–travel choices in the travel demand domain, and individual vehicles on networks in the network supply modeling domain. Although many previous applications of integrated transport demand–supply models have relied on a sequential coupling of the models, the system presented in this paper involves a dynamic integration of the activity–travel demand model and the dynamic traffic assignment and simulation model with appropriate feedback to the land use model system. The system has been fully implemented, and initial results of model system runs in a case study test application suggest that the proposed model design provides a robust behavioral framework for simulation of human activity–travel behavior in space, time, and networks. The paper provides a detailed description of the design, together with results from initial test runs.

Reexamining the Influence of Work and Nonwork Accessibility on Residential Location Choices with a Microanalytic Framework

The concept of accessibility has long been theorized as a principal determinant of residential choice behavior. Research on this influence is extensive but the empirical results have been mixed, with some research suggesting that accessibility is becoming a relatively insignificant influence on housing choices. Further, the measurement of accessibility must contend with complications arising from the increasing prevalence of trip chains, nonwork activities, and multiworker households, and also reconcile person-specific travel needs with household residential decisions. With this paper we contribute to the literature by addressing the gap framed by these issues and present a novel residential choice model with three main elements of innovation. First, we operationalize a time–space prism (TSP) accessibility measure, which we believe to be the first application of its kind in a residential choice model. Second, we represent the choice sets in a building-level framework—the lowest level of spatial disaggregation available for modeling residential choices. Third, we explicitly examine the influence of nonwork accessibility at both the local and the person level. This residential choice model is applied in the central Puget Sound region using a 2006 household activity survey. The model estimation results confirm that accessibility remains an important influence, with individual-specific work accessibility as the most critical consideration. By using the TSP approach we establish that nonwork accessibility in a trip-chaining context does contribute to the residential choice decision, even after accounting for work accessibility. Empirical tests also reveal a useful aggregation method to incorporate individual-specific accessibility measures into a household-level choice model.

Equilibrium versus Dynamics in Urban Modelling

The use of equilibrium formulations in urban modelling is increasingly challenged by models that explicitly address the dynamics of urban change. Equilibrium models assume that urban land use and transport converge to equilibrium between supply and demand and focus on comparative static analysis of these equilibria. Dynamic models consider the different speeds of processes of urban change and concentrate on their outcomes over time and the path dependence this implies. It is becoming increasingly apparent that without understanding the inherent inertia of different subsystems of cities it is impossible to assess their likely responses to land-use or transport policies. With new challenges from energy scarcity and climate change, the time horizon of urban planning is extending beyond the present generation; this makes a long-term perspective of urban models even more important. In this paper our aim is to revive the debate on whether modelling intended to inform decision making can reasonably represent cities as if they were in or near equilibrium or whether it needs to recognise explicitly that they are continuously changing and far from equilibrium. We start with a classification of urban change processes by speed of adjustment and show how equilibrium models fail to deal with them. We discuss options of modelling dynamics and argue for recursive dynamics or quasi-dynamics as a rational trade-off between theory and operationality in spatially disaggregate urban models. We illustrate this by comparing how three existing recursive or quasi-dynamic urban models address temporal dynamics and close by suggesting research needs.

The politics of sustainable development opposition: State legislative efforts to stop the United Nation’s Agenda 21 in the United States

The Tea Party exploded on the US political scene with President Barack Obama’s election and scholarly research focuses on its role in national issues. However, Tea Party and property rights advocates, among others, also fiercely oppose sustainability city planning issues, recently having legislation introduced in 26 US states to stop such practices. They perceive planning as directly connected to the United Nation’s 1992 document, Agenda 21: the Rio Declaration on Development and Environment. The counter-narrative suggests the UN seeks to restrict individual property rights and American sovereignty. Meanwhile, Agenda 21-related planning is favourably considered and practiced worldwide. Through a mixed-methods approach using quantitative and case-based research, we track the opposition’s emergence through the introduction and sometimes adoption of state legislation. We draw conclusions and implications for research and practice using a theoretical framework routed in scholarship from planning, geography, political science, and communications/new media.

Modeling Residential Location in UrbanSim

This chapter provides a description of the residential location component of UrbanSim, drawing on applications of UrbanSim in numerous metropolitan areas. The first section provides an overview of the UrbanSim system, with particular attention to the role of the residential location choice model within it. The second section describes the Open Platform for Urban Simulation, and explains how choice models in general, and more specifically residential location choice models, are created in this framework. The third section provides a comparison of recent applications of the UrbanSim residential location choice framework, along with lessons learned. The final section summarizes the current status of the model system and outlines current development efforts.

Incremental Integration of Land Use and Activity-Based Travel Modeling: Workplace Choices and Travel Demand

Recent advances in activity-based travel modeling and integrated land use and transportation modeling have significantly advanced the understanding of and the capacity to model location choices and travel behavior more realistically. These advances, however, come with greater data requirements, and the risk and the substantial cost involved with adoption of these models have slowed their move to operational use. The purpose of this research was twofold. First, the study addressed one aspect of an incremental approach that more carefully balanced the risks and benefits of moving operational models in new directions: replacement of the choice model of home-based work destination in the four-step travel model system with a pair of choice models at the level of the individual worker. The new choice models were implemented as long-term choices in the linked land use model system. Second, the models were used to provide a way to derive matches between workers and their workplace with commonly available data. These matches complemented synthetic populations and provided a key input for activity-based travel models. The models predicted whether a worker would choose to work at home on a long-term basis; if he or she did not, an out-of-home job was chosen. These models linked an individual worker to a specific job at a workplace and therefore directly predicted commuting patterns. The paper presents the model specifications, estimation results, and results of validation of the models against observed commuting data from the Census Transportation Planning Package. The model reproduced observed commuting flows well, and computational performance was fast, even though the model operated at the level of the individual worker and job.