23 CFR § 650.503 - Applicability.

---
identifier: "/us/cfr/t23/s650.503"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "23 CFR § 650.503 - Applicability."
title_number: 23
title_name: "Highways"
section_number: "650.503"
section_name: "Applicability."
chapter_name: "FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "G"
subchapter_name: "ENGINEERING AND TRAFFIC OPERATIONS"
part_number: "650"
part_name: "BRIDGES, STRUCTURES, AND HYDRAULICS"
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. 119, 144, and 315."
cfr_part: "650"
---


# 650.503 Applicability.

The National Tunnel Inspection Standards (NTIS) in this subpart apply to all structures defined as highway tunnels on all public roads, on and off Federal-aid highways, including tribally and federally owned tunnels.