PROBLEMS WITH THE TREATMENT OF TIME IN THE TRAVEL COST METHOD

Research Methods/ Statistical Methods,

EFFECTS OF ENVIRONMENTAL CHANGE ON RECREATION USE AND VALUE: AN APPLICATION TO OFFSHORE RIGS IN CALIFORNIA

Environmental Economics and Policy,

Integrated mass transportation system study/definition/implementation program definition

Specific actions needed to plan and effect transportation system improvements are identified within the constraints of limited financial, energy and land use resources, and diverse community requirements. A specific program is described which would develop the necessary generalized methodology for devising improved transportation systems and evaluate them against specific criteria for intermodal and intramodal optimization. A consistent, generalized method is provided for study and evaluation of transportation system improvements

Methodological and empirical challenges in modelling residential location choices

The modelling of residential locations is a key element in land use and transport planning. There are significant empirical and methodological challenges inherent in such modelling, however, despite recent advances both in the availability of spatial datasets and in computational and choice modelling techniques. One of the most important of these challenges concerns spatial aggregation. The housing market is characterised by the fact that it offers spatially and functionally heterogeneous products; as a result, if residential alternatives are represented as aggregated spatial units (as in conventional residential location models), the variability of dwelling attributes is lost, which may limit the predictive ability and policy sensitivity of the model. This thesis presents a modelling framework for residential location choice that addresses three key challenges: (i) the development of models at the dwelling-unit level, (ii) the treatment of spatial structure effects in such dwelling-unit level models, and (iii) problems associated with estimation in such modelling frameworks in the absence of disaggregated dwelling unit supply data. The proposed framework is applied to the residential location choice context in London. Another important challenge in the modelling of residential locations is the choice set formation problem. Most models of residential location choices have been developed based on the assumption that households consider all available alternatives when they are making location choices. Due the high search costs associated with the housing market, however, and the limited capacity of households to process information, the validity of this assumption has been an on-going debate among researchers. There have been some attempts in the literature to incorporate the cognitive capacities of households within discrete choice models of residential location: for instance, by modelling households’ choice sets exogenously based on simplifying assumptions regarding their spatial search behaviour (e.g., an anchor-based search strategy) and their characteristics. By undertaking an empirical comparison of alternative models within the context of residential location choice in the Greater London area this thesis investigates the feasibility and practicality of applying deterministic choice set formation approaches to capture the underlying search process of households. The thesis also investigates the uncertainty of choice sets in residential location choice modelling and proposes a simplified probabilistic choice set formation approach to model choice sets and choices simultaneously. The dwelling-level modelling framework proposed in this research is practice-ready and can be used to estimate residential location choice models at the level of dwelling units without requiring independent and disaggregated dwelling supply data. The empirical comparison of alternative exogenous choice set formation approaches provides a guideline for modellers and land use planners to avoid inappropriate choice set formation approaches in practice. Finally, the proposed simplified choice set formation model can be applied to model the behaviour of households in online real estate environments.Open Acces

A PROPOSED METHODOLOGY FOR ESTIMATING ECOREGIONAL VALUES FOR OUTDOOR RECREATION IN THE UNITED STATES

This paper provides a methodology for the estimation of recreational demand functions and values using an ecoregional approach. Ten ecoregions in the continental US were defined based on similarly functioning ecosystem characters. The individual travel cost method was employed to estimate the recreational demand functions for activities such as motorboating and waterskiing, developed and primative camping, coldwater fishing, sightseeing and pleasure driving, and big game hunting for each ecoregions. Estimates of per trip net income value range from $12.93 to$218.38 while per day estimates range from $4.31 to$109.19. While our ecoregional approach differs conceptually from previous work, our results appear consistent with the previous travel cost method valuation studies. (Missing tables 1,2,3,4,5 and 6)Recreation, ecoregion, travel cost method, truncated poisson model, Resource /Energy Economics and Policy,

Relationship between specific (dis)utility and the frequency of driving a car

An interesting issue in contemporary travel behavior research is whether the transportation demand has to be considered purely derived from underlying activity patterns or whether a utility is also associated with traveling per se. In the latter case, substantial amendments of current planning models would be needed to represent this phenomenon adequately. Earlier research consistently gave evidence of the existence of this specific utility, but its quantification is hindered by a specific measurement problem because survey respondents tend to mingle the utility of traveling and the utility of reaching a destination. The present work defines a methodology to quantify the decrement in the specific utility of driving a car due to the presence of difficulties and self-limiting behaviors. This is in turn responsible for an alteration of driving frequency. A structural equation modeling technique is used for the analysis. The structural submodel represents the complex relationships between socio-economic variables, specific utility, and driving frequency. The measurement submodel defines the specific utility on the basis of reported self-evaluations concerning physical fitness and self-limiting behaviors while driving. An application of the method based on data collected in the 2002 National Transportation Availability and Use Survey is presented. The results show that the decrement of specific utility (which can be seen as a disutility) of driving a car has an important impact on the frequency of performing this activity compared with the derived utility that is customarily modeled through socioeconomic variables

How to incorporate the spatial dimension within destination choice models? The case of Antwerpen

This paper considers different alternatives for including spatial aspects within the activity-based approach for modeling destination choices. The study area is the urban agglomeration of Antwerpen (Belgium); the city and its suburbs are considered. Individual travel surveys are used. The paper pays particular attention to the inclusion of space within the decision context by including specific land-use explanatory variables generated by Geographical Information Systems. A preliminary geographical analysis is performed in order to represent the city by a limited set of destinations (n = 33) and to characterize those zones in terms of land use. Discrete choice modelling is used: each individual faces the total set of spatial destination alternatives. Several modelling approaches are explored and compared in terms of utility function (for instance Box-Cox; random coefficients) and in terms of global formulation (multinomial logit versus nested logit). The mixed nested logit formulation is selected as best and the parameter estimations are interpreted; it shows the importance of space within destination choices. This paper provides a useful background for decision-makers and planners of transportation policy related to individual mobility patterns. Keywords Discrete choice model, activity-based approach, GIS, land use, urban mobility, Antwerpen

TRAVEL COST METHODS FOR ESTIMATING THE RECREATIONAL USE BENEFITS OF ARTIFICIAL MARINE HABITAT

The growing popularity of marine recreational fishing has created considerable interest in artificial marine habitat development to maintain and enhance coastal fishery stocks. This paper provides a comparative evaluation of travel cost methods to estimate recreational use benefits for new habitat site planning. Theoretical concerns about price and quality effects of substitute sites, corner solutions in site choice, and econometric estimation are considered. Results from a case study indicate that benefit estimates are influenced by the way these concerns are addressed, but relatively simple single site models can provide defensible estimates. Practical limitations on data collection and model estimation are also considered.Resource /Energy Economics and Policy,

Specifying, Estimating and Validating a New Trip Generation Model: Case Study in Montgomery County, Maryland

This paper discusses the development of an afternoon peak period trip generation model for both work and non-work trips. Three data sources are used in model development, a Household Travel Survey, a Census-Update Survey, and a Trip Generation Study. Seven one-direction trip purposes are defined, specifically accounting for stops made on the return trip from work to home. Trips are classified by origin and destination activities rather than by production and attraction, so reframing the conventional schema of home-based and non-home-based trips. Prior to estimating the model, the Household Travel Survey was demographically calibrated against the Census-Update to minimize demographic bias. A model of home-end trip generation is estimated using the Household Travel Survey as a cross-classification of the demographic factors of age and household size in addition to dwelling type. Non-home-end generation uses employment by type and population. The model was validated by comparison with a site based Trip Generation Study, which revealed an under-reporting of the relatively short and less regular shopping trips. Normalization procedures are developed to ensure that all ends of a chained trip were properly accounted for. .