23 CFR § 1340.3 - Definitions.

---
identifier: "/us/cfr/t23/s1340.3"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "23 CFR § 1340.3 - Definitions."
title_number: 23
title_name: "Highways"
section_number: "1340.3"
section_name: "Definitions."
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"
---


# 1340.3 Definitions.

As used in this part—

*Access ramp* means the segment of a road that forms a cloverleaf or limited access interchange.

*Cul-de-sac* means the closed end of a road that forms a loop or turn-around.

*Non-public road* means a road on which members of the general public are not allowed to drive motor vehicles.

*Nonresponse rate* means, for any survey variable, the percentage of unknown values recorded for that variable.

*Observation site* means the physical location where survey data are collected.

*Passenger motor vehicle* means a motor vehicle with a gross vehicle weight rating of less than 10,000 pounds, including a passenger car, pickup truck, van, minivan or sport utility vehicle.

*Service drive* means the segment of a road that provides access to businesses and rest areas.

*Traffic circle* means the segment of a road or intersection of roads forming a roundabout.

*Unnamed road* means a road, public or private, that has no name or number designation and is often a farm or logging road.

*Vehicular trail* means a road designed or intended primarily for use by motor vehicles with four-wheel drive.