---
kind: "unit"
title: "23"
title_heading: "Highways"
key: "chI/subchE"
level: "subchap"
label: "Subchapter E"
heading: "Planning and Research"
release: "ecfr-current"
date: "2026-08-27"
url: "https://uscodex.org/cfr/23/chI-subchE"
sections_count: 123
---

# Subchapter E — Planning and Research

Title 23 C.F.R. — Highways › Chapter I — Federal Highway Administration, Department of Transportation

## Contents

- [Part 420 — Planning and Research Program Administration](/cfr/23/chI-subchE-part420.md)
- [Part 450 — Planning Assistance and Standards](/cfr/23/chI-subchE-part450.md)
- [Part 460 — Public Road Mileage for Apportionment of Highway Safety Funds](/cfr/23/chI-subchE-part460.md)
- [Part 470 — Highway Systems](/cfr/23/chI-subchE-part470.md)
- [Part 490 — National Performance Management Measures](/cfr/23/chI-subchE-part490.md)