23 C.F.R. § 1340.5 Documentation requirements.
Title 23 - Highways
All sample design, data collection, and estimation procedures used in State surveys conducted in accordance with this part must be well documented. At a minimum, the documentation must: (a) For sample design— (1) Define all sampling units, with their measures of size; (2) Define what stratification was used at each stage of sampling and what methods were used for allocation of the sample units to the strata; (3) Explain how the sample size at each stage was determined; (4) List all samples units and their probabilities of selection; and (5) Describe how observation sites were assigned to observation time periods. (b) For data collection— (1) Define an observation period; (2) Define an observation site and what procedures were implemented when the observation site was not accessible on the date assigned; (3) Describe what vehicles were observed and what procedures were implemented when traffic was too heavy to observe all vehicles; and (4) Describe the data recording procedures. (c) For estimation— (1) Display the raw data and the weighted estimates; (2) For each estimate, provide an estimate of one standard error and an approximate 95 percent confidence interval; and (3) Describe how estimates were calculated and how variances were calculated.
Title 23: Highways
PART 1340—UNIFORM CRITERIA FOR STATE OBSERVATIONAL SURVEYS OF SEAT BELT USE
§ 1340.5 Documentation requirements.
