Value of business travel time

This paper investigates the allocation of household individuals to out-of-home maintenance activities using the rich activity-travel diary data from the San Francisco Bay Area. Two inter-related decisions are considered in this context: (i) whether the given activity episode is performed individually (solo) or jointly, and (ii) the person who participates in the activity, if it is a solo activity. To account for the conditional nature of the solo activity person selection, a nested mixed logit modeling framework is proposed and implemented to jointly analyze person allocation for all maintenance activities performed by a household on a given day. The model is used to investigate within-household effects and between-household differences. The proposed model relaxes some important restrictions in person allocation models by accounting for various sources of correlations and relaxing the assumption of constant variance across households. The proposed model is used to analyze the differences in person allocation between different types of households. The results indicate that life-cycle and household role, income, gender, employment status, and several types of constraints (activities including cost, time-availability, vehicle-availability, coordination constraints, and child-care obligations) affect person allocation decisions in the context of maintenance activities. The empirical results indicate the presence of various sources of correlations across persons, over activities, and within-household that are significant. In addition, the data also provides evidence that the unobserved variances in person selection utilities are not constant across households. A better understanding of these within-household interactions and between-household differences may be used in activity-based simulation models and to develop more effective and focused demand management measures.

Analysis of Within-Household Effects and Between-Household Differences in Maintenance Activity Allocation

A model system of trip generation and trip chaining was developed by integrating concepts from activity-based analysis. The structure of the model system is recursive, depicting a sequential decision-making mechanism. The results were based on a data set from the Detroit metropolitan area. They were compared with those of a previous study that used a data set from the Netherlands. Differences were observed not only in the values of the regression parameters estimated but also in the decision mechanism inferred.

Practical Method for The Estimation of Trip Generation And Trip Chaining

Activity-based approaches to travel demand analysis have gained attention in the past few years and rapidly created the need to develop alternative microsimulation models for comparisons. In this paper, one such example simulates an individual's daily activity-travel patterns and incorporates the interactions among members of households. This model uses several tools to simulate the activity patterns, including a new method to extract activity patterns from data and decision trees to take into account personal and household characteristics. The model outputs are the individuals' daily activity patterns on a detailed temporal scale. These patterns respect individuals' constraints, which are implicitly embedded in the simulated activity and travel schedules via the intrahousehold interactions. This model was evaluated with data from 1,500 persons in Centre County, Pennsylvania, collected during fall 2002 and spring 2003.

Simulation of Daily Activity Patterns Incorporating Interactions Within Households: Algorithm Overview and Performance

This paper presents a model simulating the daily activity patterns of individuals and their households. One of the important features of the model is its ability to simulate activities that can be conducted either alone or togetherr with others. As the models are based on activity participation and affect other features of the model, the interactions are essential. Cluster analysis is used to classify activity patterns. To consider both personal and household characteristic, the paper uses decision trees,

Simulation of Daily Activity Patterns

Tests of four hypotheses relating to allocation of activities and time among household members are described using two data sets from two urban regions—Boston, Massachusetts, and Salt Lake City, Utah. The first hypothesis is a test of categorizing activities into groups of mandatory, flexible, and optional activities; this hypothesis is upheld by the data. The second hypothesis is a test of whether there are significant differences in the mean time allocations of activities among the life-cycle groups. It was found that the life-cycle groups that were used do provide a basis for identifying significantly different time allocations to different activities within all three groups of activities. The third hypothesis concerns the relative allocation of time by gender within households for optional and flexible activities, across the life-cycle groups. It was found that gender shows effects on time allocation, but these effects are limited to a few activities, and others show no such effects. The fourth hypoth...

Household Activities, Life Cycle, and Role Allocation Tests on Data Sets from Boston and Salt Lake City

A feasibility study of a system of high-speed rail lines for the kingdom of Thailand is described. Absent comprehensive local data and any intercity forecasting models for the nation, an incremental demand model and an incremental mode-choice model were chosen as the modeling techniques to use for the study. The incremental demand model used variables of population, gross provincial product, and the log sum term of level of service from the mode-choice model. The mode-choice model itself was synthesized using parameter values from similar efforts in other countries, adjusted to local currency values and income per capita. The steps taken to estimate base-year demand and market shares are described, and the application of the models to forecasting demand for four alternative technologies is discussed. Within the context of the input forecasts of population and gross domestic product, the models were found to produce reasonable results, with intuitively appropriate sensitivities. The results were also found...

Helen M. A. Metcalf

Papers

Household Activities, Life Cycle, and Role Allocation Tests on Data Sets from Boston and Salt Lake City

Estimating patronage for a feasibility study of high-speed rail in thailand