Multiday Samples,Parameter Estimation Precision,and Data Collection Costs for Least Squares Regression Trip-Generation Models

Abstract

In this paper it is shown that substantial benefits may be achieved by employing a multiday sample in least squares estimation of linear regression models of travel behaviour. Specifically, by using a multiday sample one can reduce data collection costs while maintaining a given level of precision in the parameter estimates, or one can obtain improved precision in the parameter estimates for a given data collection cost. Furthermore there is an optimal length of observation period that either minimizes the cost of data collection (for a given level of precision in the parameter estimates) or maximizes the precision of the parameter estimates (for a given data collection cost). The characteristics of the optimal multiday sample depend on the cost structure of data collection and the degree of intrapersonal variability in the aspect of travel behavior being modeled. The results also clearly show the superiority of two-day samples relative to traditional single-day samples, under a wide variety of circumstances. Empirical analysis, using data collected in Reading, England, is used to verify the analytic relationships and to assess the benefits of multiday samples in a particular context.

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References

Clarke

M I

Dix

M C

Jones

P M

, 1981, “Error and uncertainty in travel surveys” Transportation 10 105–126

Downes

J D

Wroot

, 1974, “1971 repeat survey of travel in the Reading area” TRRL SR 43 UC, Department of the Environment, 2 Marsham Street, London SW1

Fuller

W A

Battese

G E

, 1974, “Estimation of linear models with crossed-error structure” Journal of Econometrics 2 67–78

Golob

T F

Meurs

, 1985, “Biases in response over time in a seven-day travel diary” manuscript available from the authors, Bureau Goudappel Coffeng B V, Parkweg 4, Deventer, The Netherlands

Hanson

Huff

J O

, 1982, “Assessing day-to-day variability in complex travel patterns” Transportation Research Record 891 18–24

Koppelman

F S

Pas

E I

, 1984, “Estimation of disaggregate regression models of person trip generation with multiday data” in Proceedings of the Ninth International Symposium on Transportation and Traffic Theory Eds Volmuller

Hamerslag

(VNU Science Press, Utrecht) pp 513–531

Pas

E I

, 1985, “An examination of temporal bias in travel information inferred from activity diary data” manuscript available from the author

Pas

E I

Koppelman

F S

, 1984, “Intrapersonal variability in weekday urban travel and related behavior: Formulation and examination of some hypotheses” paper presented at the 63rd Annual Meeting of the Transportation Research Board, Washington, DC; copy available from the first author

SAS, 1980 SAS Supplemental Library Users Guide Statistical Analysis System Institute Inc., PO Box 8000, Cary, NC 27511

10.

Shapcott

, 1978, “Comparison of the use of time in Reading, England, with time use in other countries” Transactions of the Martin Centre for Architectural and Urban Studies 3 231–257