23 CFR § 1340.6 - Assignment of observation times.

---
identifier: "/us/cfr/t23/s1340.6"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "23 CFR § 1340.6 - Assignment of observation times."
title_number: 23
title_name: "Highways"
section_number: "1340.6"
section_name: "Assignment of observation times."
chapter_name: "NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
part_number: "1340"
part_name: "UNIFORM CRITERIA FOR STATE OBSERVATIONAL SURVEYS OF SEAT BELT USE"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "23 U.S.C. 402; delegation of authority at 49 CFR 1.50."
regulatory_source: "76 FR 18056, Apr. 1, 2011, unless otherwise noted."
cfr_part: "1340"
---


# 1340.6 Assignment of observation times.

(a) *Daylight hours.* All daylight hours between 7 a.m. and 6 p.m. for all days of the week shall be eligible for inclusion in the sample.

(b) *Random assignment.* Except as provided in paragraph (c) of this section, the day-of the week and time-of-the-day shall be randomly assigned to observation sites.

(c) *Grouping of observation sites in close geographic proximity.* Observations sites in close geographic proximity may be grouped to reduce data collection burdens if:

(1) The first assignment of an observation site within the group is randomly selected; and

(2) The assignment of other observations sites within the group is made in a manner that promotes administrative efficiency and timely completion of the survey.