23 C.F.R. § 1340.4 Population, demographic, and time/day requirements.
Title 23 - Highways
Surveys conducted in accordance with this part shall comply with the following minimum population, demographic, and time/day requirements: (a) Population of interest. (1) Drivers and front seat outboard passengers in passenger motor vehicles (passenger cars, pickup trucks, vans, and sport utility vehicles) must be observed in the survey. (Only overall restraint use for the population of interest is required. However, in order to assist in the evaluation of trends, it is recommended that data be collected in such a way that restraint use estimates can be reported separately for passenger cars and other covered vehicles, and separately for drivers and front-seat outboard passengers within those vehicle groups.) (2) Surveys conducted during calendar year 1998 shall be deemed to comply with paragraph (a)(1) of this section if passenger motor vehicles registered in-State are included in the survey. For surveys conducted during calendar year 1999 and thereafter, passenger motor vehicles registered both in-state and out-of-state must be included in the survey. (b) Demographics. Counties, or other primary sampling units, totaling at least 85 percent of the State's population must be eligible for inclusion in the sample. States may eliminate their least populated counties, or other primary sampling units, to a total of fifteen percent or less of the total State population, from the sampling frame. (c) Time of day and day of week. All daylight hours for all days of the week must be eligible for inclusion in the sample. Observation sites must be randomly assigned to the selected day-of-week/time-of-day time slots. If observation sites are grouped to reduce data collection burdens, a random process must be used to make the first assignment of a site within a group to an observational time period. Thereafter, assignment of other sites within the group to time periods may be made in a manner that promotes administrative efficiency and timely completion of the survey. [63 FR 46392, Sept. 1, 1998, as amended at 65 FR 13683, Mar. 14, 2000]
Title 23: Highways
PART 1340—UNIFORM CRITERIA FOR STATE OBSERVATIONAL SURVEYS OF SEAT BELT USE
§ 1340.4 Population, demographic, and time/day requirements.
