# 道路運送車両法 / Road Transport Vehicle Act — 第六十三条の三 (Article 63-3)

- Law: 道路運送車両法 (Road Transport Vehicle Act), 昭和二十六年法律第百八十五号
- English title "Road Transport Vehicle Act": Ministry of Justice translation database, which lists the title
- Kind: Act — the distinction between 法律 (Act), 政令 (Cabinet Order), 省令 (Ministerial Order) and 条例 (local ordinance) decides who may issue it and what it may say.
- Provision: 第六十三条の三 (Article 63-3)（改善措置の届出等） — address `art-63-3`
- Text in force since: 2026-04-01
- URL (the page that opens at this provision): https://japanlaw.org/en/road-transport-vehicle-act/art-63-3
- Permanent URL (e-Gov law ID, never renamed): https://japanlaw.org/l/326AC0000000185/art-63-3
- Every provision below carries its address and both URLs on the line under it.
- Japanese text: e-Gov 法令検索, Digital Agency (デジタル庁). English: as marked on each line below.

Only the Japanese as published by the government has legal effect; the text
below is a copy of it. Every English rendering below is a translation and
says which kind: the Ministry of Justice's translation, or this
site's machine translation, whose model and date the Sources list names.
They are never merged and never substituted for one another.

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### 第六十三条の三（改善措置の届出等） — Notification of Improvement Measures, etc.
<sup>caption: machine translation, not official</sup>
<sup>art-63-3 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3 · https://japanlaw.org/l/326AC0000000185/art-63-3</sup>

**第一項**  自動車製作者等は、その製作し、又は輸入した同一の型式の一定の範囲の自動車の構造、装置又は性能が保安基準に適合しなくなるおそれがある状態又は適合していない状態にあり、かつ、その原因が設計又は製作の過程にあると認める場合において、当該自動車について、保安基準に適合しなくなるおそれをなくするため又は保安基準に適合させるために必要な改善措置を講じようとするときは、あらかじめ、国土交通大臣に次に掲げる事項を届け出なければならない。
<sup>art-63-3/par-1 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1</sup>
When a motor vehicle manufacturer, etc. finds that the structure, equipment or performance of a certain range of motor vehicles of the same model that it manufactured or imported is in a condition in which it is likely to cease to conform to the safety standards or does not conform to them and that the cause lies in the process of design or manufacture, and intends to take the improvement measures necessary to eliminate the likelihood of those motor vehicles ceasing to conform to the safety standards or to make them conform to the safety standards, it must notify the Minister of Land, Infrastructure, Transport and Tourism in advance of the following matters:
<sup>machine translation, not official</sup>

  **一**  保安基準に適合しなくなるおそれがある状態又は適合していない状態にあると認める構造、装置又は性能の状況及びその原因
  <sup>art-63-3/par-1/item-1 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1/item-1 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1/item-1</sup>
  the status of the structure, equipment or performance found to be in a condition in which it is likely to cease to conform to the safety standards or does not conform to them, and its cause;
  <sup>machine translation, not official</sup>

  **二**  改善措置の内容
  <sup>art-63-3/par-1/item-2 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1/item-2 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1/item-2</sup>
  the details of the improvement measures; and
  <sup>machine translation, not official</sup>

  **三**  前二号に掲げる事項を当該自動車の使用者に周知させるための措置その他の国土交通省令で定める事項
  <sup>art-63-3/par-1/item-3 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1/item-3 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1/item-3</sup>
  measures to make the matters listed in the preceding two items known to the users of those motor vehicles, and other matters specified by Order of the Ministry of Land, Infrastructure, Transport and Tourism.
  <sup>machine translation, not official</sup>

**第二項**  装置製作者等は、その製作し、又は輸入した同一の型式の一定の範囲の特定後付装置が保安基準に適合しなくなるおそれがある状態又は適合していない状態にあり、かつ、その原因が設計又は製作の過程にあると認める場合において、当該特定後付装置について、保安基準に適合しなくなるおそれをなくするため又は保安基準に適合させるために必要な改善措置を講じようとするときは、あらかじめ、国土交通大臣に次に掲げる事項を届け出なければならない。
<sup>art-63-3/par-2 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2</sup>
When an equipment manufacturer, etc. finds that a certain range of specified aftermarket devices of the same model that it manufactured or imported are in a condition in which they are likely to cease to conform to the safety standards or do not conform to them and that the cause lies in the process of design or manufacture, and intends to take the improvement measures necessary to eliminate the likelihood of those specified aftermarket devices ceasing to conform to the safety standards or to make them conform to the safety standards, it must notify the Minister of Land, Infrastructure, Transport and Tourism in advance of the following matters:
<sup>machine translation, not official</sup>

  **一**  保安基準に適合しなくなるおそれがある状態又は適合していない状態にあると認める特定後付装置の状況及びその原因
  <sup>art-63-3/par-2/item-1 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2/item-1 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2/item-1</sup>
  the status of the specified aftermarket devices found to be in a condition in which they are likely to cease to conform to the safety standards or do not conform to them, and their cause;
  <sup>machine translation, not official</sup>

  **二**  改善措置の内容
  <sup>art-63-3/par-2/item-2 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2/item-2 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2/item-2</sup>
  the details of the improvement measures; and
  <sup>machine translation, not official</sup>

  **三**  前二号に掲げる事項を当該特定後付装置の使用者に周知させるための措置その他の国土交通省令で定める事項
  <sup>art-63-3/par-2/item-3 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2/item-3 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2/item-3</sup>
  measures to make the matters listed in the preceding two items known to the users of those specified aftermarket devices, and other matters specified by Order of the Ministry of Land, Infrastructure, Transport and Tourism.
  <sup>machine translation, not official</sup>

**第三項**  国土交通大臣は、第一項又は前項の規定による届出に係る改善措置の内容が、当該自動車又は特定後付装置について、保安基準に適合しなくなるおそれをなくするため又は保安基準に適合させるために適切でないと認めるときは、当該届出をした自動車製作者等又は装置製作者等に対し、その変更を指示することができる。
<sup>art-63-3/par-3 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-3 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-3</sup>
When the Minister of Land, Infrastructure, Transport and Tourism finds that the details of the improvement measures relating to a notification under paragraph (1) or the preceding paragraph are not appropriate to eliminate the likelihood of those motor vehicles or specified aftermarket devices ceasing to conform to the safety standards or to make them conform to the safety standards, the Minister may instruct the motor vehicle manufacturer, etc. or equipment manufacturer, etc. that made the notification to change them.
<sup>machine translation, not official</sup>

**第四項**  第一項の規定による届出をした自動車製作者等又は第二項の規定による届出をした装置製作者等は、国土交通省令で定めるところにより、当該届出に係る改善措置の実施状況について国土交通大臣に報告しなければならない。
<sup>art-63-3/par-4 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-4 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-4</sup>
A motor vehicle manufacturer, etc. that made a notification under paragraph (1) or an equipment manufacturer, etc. that made a notification under paragraph (2) must, as prescribed by Order of the Ministry of Land, Infrastructure, Transport and Tourism, report to the Minister of Land, Infrastructure, Transport and Tourism on the status of implementation of the improvement measures relating to the notification.
<sup>machine translation, not official</sup>

**第五項**  国土交通大臣は、第三項の規定による指示を行おうとする場合において必要があると認めるときは、自動車の構造、装置若しくは性能又は特定後付装置について、保安基準に適合しなくなるおそれをなくするため又は保安基準に適合させるために、第一項又は第二項の規定による届出に係る改善措置の内容が適切であるかどうかの技術的な検証を機構に行わせるものとする。
<sup>art-63-3/par-5 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-5 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-5</sup>
When the Minister of Land, Infrastructure, Transport and Tourism intends to give an instruction under paragraph (3) and finds it necessary, the Minister is to have the Agency conduct a technical verification of whether the details of the improvement measures relating to a notification under paragraph (1) or (2) are appropriate, with respect to the structure, equipment or performance of motor vehicles, or specified aftermarket devices, to eliminate the likelihood of ceasing to conform to the safety standards or to make them conform to the safety standards.
<sup>machine translation, not official</sup>

**第六項**  機構は、前項の技術的な検証を行つたときは、遅滞なく、当該技術的な検証の結果を国土交通大臣に通知しなければならない。
<sup>art-63-3/par-6 · https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-6 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-6</sup>
When the Agency has conducted the technical verification under the preceding paragraph, it must without delay notify the Minister of Land, Infrastructure, Transport and Tourism of the result of that technical verification.
<sup>machine translation, not official</sup>

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## Cites
- art-63-3/par-1/item-3: 前二号 → 道路運送車両法 第六十三条の三第一項第一号 (Article 63-3, paragraph (1), item (i)), art-63-3/par-1/item-1 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1/item-1 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1/item-1
- art-63-3/par-1/item-3: 前二号 → 道路運送車両法 第六十三条の三第一項第二号 (Article 63-3, paragraph (1), item (ii)), art-63-3/par-1/item-2 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1/item-2 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1/item-2
- art-63-3/par-2/item-3: 前二号 → 道路運送車両法 第六十三条の三第二項第一号 (Article 63-3, paragraph (2), item (i)), art-63-3/par-2/item-1 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2/item-1 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2/item-1
- art-63-3/par-2/item-3: 前二号 → 道路運送車両法 第六十三条の三第二項第二号 (Article 63-3, paragraph (2), item (ii)), art-63-3/par-2/item-2 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2/item-2 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2/item-2
- art-63-3/par-3: 第一項 → 道路運送車両法 第六十三条の三第一項 (Article 63-3, paragraph (1)), art-63-3/par-1 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1
- art-63-3/par-3: 前項 → 道路運送車両法 第六十三条の三第二項 (Article 63-3, paragraph (2)), art-63-3/par-2 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2
- art-63-3/par-4: 第一項 → 道路運送車両法 第六十三条の三第一項 (Article 63-3, paragraph (1)), art-63-3/par-1 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1
- art-63-3/par-4: 第二項 → 道路運送車両法 第六十三条の三第二項 (Article 63-3, paragraph (2)), art-63-3/par-2 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2
- art-63-3/par-5: 第三項 → 道路運送車両法 第六十三条の三第三項 (Article 63-3, paragraph (3)), art-63-3/par-3 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-3 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-3
- art-63-3/par-5: 第一項 → 道路運送車両法 第六十三条の三第一項 (Article 63-3, paragraph (1)), art-63-3/par-1 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1
- art-63-3/par-5: 第二項 → 道路運送車両法 第六十三条の三第二項 (Article 63-3, paragraph (2)), art-63-3/par-2 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2
- art-63-3/par-6: 前項 → 道路運送車両法 第六十三条の三第五項 (Article 63-3, paragraph (5)), art-63-3/par-5 — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-5 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-5

## Cited by

14 provisions cite this one. No official source publishes this direction.

- 道路運送車両法 第六十三条の二第一項（改善措置の勧告等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-2/par-1 · https://japanlaw.org/l/326AC0000000185/art-63-2/par-1
- 道路運送車両法 第六十三条の二第二項（改善措置の勧告等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-2/par-2 · https://japanlaw.org/l/326AC0000000185/art-63-2/par-2
- 道路運送車両法 第六十三条の二第三項（改善措置の勧告等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-2/par-3 · https://japanlaw.org/l/326AC0000000185/art-63-2/par-3
- 道路運送車両法 第六十三条の三第一項第三号（改善措置の届出等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-1/item-3 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-1/item-3
- 道路運送車両法 第六十三条の三第二項第三号（改善措置の届出等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-2/item-3 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-2/item-3
- 道路運送車両法 第六十三条の三第三項（改善措置の届出等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-3 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-3
- 道路運送車両法 第六十三条の三第四項（改善措置の届出等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-4 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-4
- 道路運送車両法 第六十三条の三第五項（改善措置の届出等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-5 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-5
- 道路運送車両法 第六十三条の三第六項（改善措置の届出等） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-3/par-6 · https://japanlaw.org/l/326AC0000000185/art-63-3/par-6
- 道路運送車両法 第六十三条の四第一項（報告及び検査） — https://japanlaw.org/en/road-transport-vehicle-act/art-63-4/par-1 · https://japanlaw.org/l/326AC0000000185/art-63-4/par-1
- 道路運送車両法 第六十四条第一項 — https://japanlaw.org/en/road-transport-vehicle-act/art-64/par-1 · https://japanlaw.org/l/326AC0000000185/art-64/par-1
- 道路運送車両法 第七十四条の四第一項 — https://japanlaw.org/en/road-transport-vehicle-act/art-74-4/par-1 · https://japanlaw.org/l/326AC0000000185/art-74-4/par-1
- 道路運送車両法 第百六条の四第一項第二号 — https://japanlaw.org/en/road-transport-vehicle-act/art-106-4/par-1/item-2 · https://japanlaw.org/l/326AC0000000185/art-106-4/par-1/item-2
- 道路運送車両法 第百十条第一項第三号 — https://japanlaw.org/en/road-transport-vehicle-act/art-110/par-1/item-3 · https://japanlaw.org/l/326AC0000000185/art-110/par-1/item-3

---

## Sources

- e-Gov 法令検索, Digital Agency (デジタル庁) — 道路運送車両法 — the text in force from 2026-04-01 (https://laws.e-gov.go.jp/law/326AC0000000185/20260401_508AC0000000002), retrieved 2026-10-13
- Japanese Law Translation Database System, Ministry of Justice (法務省) — 道路運送車両法 — its English title as the Ministry of Justice's translation database lists it (https://www.japaneselawtranslation.go.jp/en/laws/view/529), retrieved 2026-09-18
- claude-sonnet-5-5 — Machine translation, batch road-transport-vehicle-act-20261013T120733-014, translated 2026-10-13
- This site's parser, version 189 — 道路運送車両法 — structure, counts, cross-references and defined terms, computed 2026-10-13