Introduction

Trip distribution has been demonstrated to be the largest source of error in traditional models used for personal travel (need reference-Zhao and Kockelman, 2002). For that reason, logit-based destination choice models have become an increasingly common replacement for gravity models to improve the accuracy of the trip distribution step. Destination choice models are potentially even more advantageous over gravity models for longer distance personal travel and multinucleated travel regions, and have therefore been widely incorporated in statewide travel models (e.g., Wisconsin, Ohio, Maryland, New Hampshire, Arizona, Oregon, Idaho, California, etc.) and larger metropolitan area travel models (e.g., XXXX).

Destination choice models are a type of trip distribution or spatial interaction model which are formulated as discrete choice models, typically logit models. They can be thought of as a generalization of the traditional and widely used gravity model. In practice, this flexible and extensible formulation allows destination choice models to provide a better behavioral basis for trip distribution than the traditional gravity models, by allowing for a wider range of explanatory variables. Although technically gravity models can be considered a subset or special case of destination choice models, the term “destination choice models” typically is used to identify models that incorporate additional variables beyond size/attractions, impedance/friction factors and constants or k-factors. (see, for example, [1][2][3][4][5][6]).


Destination choice models have consistently demonstrated the ability to better reproduce observed, personal travel patterns than gravity models, both through the incorporation of additional variables, as well as by reflecting more complex statistical assumptions, such as capturing spatial autocorrelation. [1]

Advantages and Limitations of Destination Choice Models

Although the gravity analogy may still be appropriate for trip distribution in mono-centric urban regions where accessibility to transit plays little to no role in choice of destination, this is no longer the case in many urban areas, where there may be more than one dominant attraction region, multiple and important suburban-to-suburban trip flows, and where there is interest in understanding the contribution of transit towards achieving more sustainable urban development patterns. The gravity model often times exhibits incorrect demand elasticities; in particular, the model may respond illogically to changes in levels of service where improved accessibility to a given destination may cause a disproportionate increase in total trips, and/or an increase in trips using the mode(s) whose accessibility did not change. Both of these results are undesirable and may lead to erroneous assessments of the impact of transit or highway improvements. Destination choice models overcome these gravity model limitations. With appropriate specifications of utility, consistency between changes in levels of service and changes in demand is guaranteed when using destination choice models. In addition, because the functional form of the destination choice utility is very flexible, accounting for singularities in the trip distribution pattern can be accomplished in intuitive ways. For example, to inform a gravity model of the presence of a natural barrier, such as a river, a K-factor is often used. With a destination choice model, a term can be added to the utility equation and interpreted in terms of equivalent minutes of travel time; a much more intuitive measure of the impact the river would have on a person's travel choice.

Another key advantage offered by destination choice models when compared to the more traditional gravity model is their ability to consider additional factors. At the same time, it is also important to recognize destination choice models in practice today still struggle to explain the spatial distribution of personal travel. This is due in large measure to the lack of data and the importance of unobserved attributes. In many cases, a destination choice model may be able to double the goodness-of-fit, or explain twice as much of the observed travel patterns than a gravity model, but in the end still explain less than half of the variation in the observed patterns.

Both the advantages and limitations of destination choice models can be understood in terms of the factors that affect travelers' destination choices based on those the models can incorporate or reflect and those they cannot. The table below describes some of these advantages and limitations.

Observed Variables Gravity Models Destination Choice Models Not in Models
Number of Households X X
Number of employees by industry X X
Travel Time and/or distance X X
River crossings, highway crossings & other known psychological barriers X
Where the traveler lives X
Traveler's income, etc. X
Proximity of similar, competing destinations X
Convenience of destinations to other attractive places X
Walkability, density, mix of uses at destinations X
Parking Prices and Availability (sometimes) X
Unobserved Variables Gravity Models Destination Choice Models Not in Models
Simple Random Variation X X
Other Traveler Attitudes / Preferences (toward price and quality of goods/services, etc.) X
Spatial Autocorrelation / Unobserved homogeneity of destinations X
Price of goods/services provided at the destination X
Quality of goods / services provided at the destination X
Occupation of workers in residences X
Social relationships (friendships, familial relations) X
History/habit (this used to be the best pizza place) X
Aesthetics X

Destination Choice Models in Practice

Destination choice models can be used in aggregate trip-based models as an alternative to gravity models or other spatial interaction models. Destination choice models are standard and ubiquitous in tour-based and activity-based models.

As of 2005, 5% of MPOs were using destination choice models, [7] mostly for trip distribution in aggregate trip-based models. As of 2014, based on a survey by TMIP, 9% of MPOs & DOTs were using a tour-based or activity-based model and an additional 17% were in the process of developing them. Destination choice models are therefore likely currently in use in approximately 15% of travel models and likely to be used in roughly a third of models in the relatively near term future.

Destination choice models have been incorporated into the travel model framework in several states and regions. For example, ..... (need to include links and descriptions to two statewide models with a link to documentation and an application as well as two or more regional models).

Destination Choice: Theoretical Foundations

(Eric's stuff)

Destination Choice: Mathematical Formulation

(Rosella's stuff) here

Destination Choice Set Formation

Joint/Conditional Destination Choices

In traditional four-step travel models, all destination choices are assumed to be independent. This is reflected in the fact that gravity or destination choice models in this context are run in parallel and independently of each other. Both activity-based, hybrid, and advanced trip-based frameworks have developed different approaches to relaxing this assumption of independence. Each of these approaches is presented here.

Factors Affecting Destination Choice

Destination Choice: Data Sources

Destination Choice: Parameter Estimation

Destination Choice: Calibration and Validation

Destination Choice: Implementation and Application

References

  1. 1.0 1.1 Bernardin, V. L., F. Koppelman, and D. Boyce. Enhanced Destination Choice Models Incorporating Agglomeration Related to Trip Chaining While Controlling for Spatial Competition. In Transportation Research Record: Journal of the Transportation Research Board of the National Academies, Washington, D.C., 2009, pp. 143-151.
  2. Chow, L.-F.,, F. Zhao, M.-T. Li, and S.-C. Li. Development and Evaluation of Aggregate Destination Choice Models for Trip Distribution in Florida. In Transportation Research Record: Journal of the Transportation Research Board of the National Academies, Washington, D.C., 2005, pp. 18-27
  3. Jonnalagadda, N., J. Freedman, W. A. Davidison, and J. D. Hunt. Development of Microsimulation Activity-Based Model for San Francisco: Destination and Mode Choice Models. In Transportation Research Record: Journal of the Transportation Research Board of the National Academies, Washington, D.C., 2001, pp. 25-35.
  4. Bhat, C., A. Govindarajan, and V. Pulugata. Disaggregate Attraction-End Choice Modeling: Formulation and Empirical Analysis. In Transportation Research Record: Journal of the Transportation Research Board of the National Academies, Washington, D.C., 1998, pp. 0-68
  5. Borgers, A., and H. Timmermans. Choice Model Specification, Substitution and Spatial Structure Effects: A Simulation Experiment. Regional Science and Urban Economics, Vol. 17, 1987, pp. 29-47
  6. Fotheringham, A. S. Some Theoretical Aspects of Destination Choice and Their Relevance to Production-Constrained Gravity Models. Environment and Planning, Vol. 15A, 1983, pp. 464-488
  7. SR 288-Metropolitan Travel Forecasting Current Practice and Future Direction

Subcategories

This category has the following 2 subcategories, out of 2 total.