23 CFR § 1340.11 - Post-approval alterations to survey design.

---
identifier: "/us/cfr/t23/s1340.11"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "23 CFR § 1340.11 - Post-approval alterations to survey design."
title_number: 23
title_name: "Highways"
section_number: "1340.11"
section_name: "Post-approval alterations to survey design."
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: "2026-03-24"
last_updated: "2026-03-24"
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"
---


# 1340.11 Post-approval alterations to survey design.

After NHTSA approval of a survey design, States shall submit for NHTSA approval any proposed alteration to their survey design, including, but not limited to, sample design, seat belt use rate estimation method, variance estimation method and data collection protocols, at least three months before data collection begins.