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UN R166 Base text (01 series) · UNECE Regulation No. 166 (ECE R166) — Uniform Provisions Concerning the Approval of Devices and Motor Vehicles with Regard to the Driver’s Awareness of Vulnerable Road Users in Close-Proximity to the Front and Lateral Sides of Vehicles.

UN R166 — 01 series of amendments

Changes from 00 series of amendments

Adopted at the WP.29 194th sessionEntry into force 2025-06-12
What changed
  • New paragraphs 6.1.3. to 6.2.4. add protective housing requirements and tests for mirrors. New paragraphs 15.4.3. to 15.4.3.6. add protective housing requirements for devices other than mirrors.
  • In paragraph 15.2., plane (a) “passing through a point 300 mm from the contour of the sides of the vehicle” is now a longitudinal vertical plane. Plane (b) at the front is now a transverse vertical plane, not a transverse horizontal plane.
  • As from 1 September 2026, Contracting Parties applying this Regulation are not obliged to accept preceding-series type approvals first issued after that date.
Why
  • The impact safety requirements for mirrors were copied from UN Regulation No. 46, which reflects the latest amendment (GRSG-126-24r1).
  • Impact safety requirements were also added for FLVCS and detection systems, the same as for mirrors.
  • The text was reorganized between paragraphs 15.1. and 15.2. for clear descriptions, and the figures on pole location were updated to avoid misinterpretation.

Q1What changed170 changes

Protective housing and tests for mirrors (paras. 6.1.3. to 6.2.4. and Annex 13)

New paragraphs 6.1.3. to 6.2.4. add protective housing requirements and tests for mirrors. Under paragraph 6.2.1., devices for mirrors are subjected to a pendulum impact test, and exterior mirrors with a stem to a bending test. Paragraphs 6.2.1.1. and 6.2.2. give cases where the impact test is not required or is not carried out. The requirements of paragraph 6.2. are considered to be satisfied for mirrors of a vehicle fulfilling the provisions of Regulation No. 21. Under paragraph 6.2.4., devices approved by UN Regulation No. 26 or No. 61 are exempted from paragraph 6.2. New Annex 13 has the title “Necessity of Pendulum Impact Test”, and paragraph 6.2.2. refers to it.

Protective housing
[figure changed]
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Activation (para. 15.4.1.), new numbers 15.4.2. to 15.4.2.4., protective housing of devices other than mirrors (para. 15.4.3.) and default view (para. 16.2.)

New paragraph 15.4.1. has the heading “Activation”, with paragraphs 15.4.1.1. and 15.4.1.2. on FLVCS and the detection system. Paragraph 15.4.1.1. says it must be possible to easily activate FLVCS and the detection system when the gear is in the out-of-parking or neutral range. Former paragraphs 15.4.1. to 15.4.1.4. are renumbered as paragraphs 15.4.2. to 15.4.2.4. New paragraphs 15.4.3. to 15.4.3.6. set protective housing requirements for devices other than mirrors. Paragraph 15.4.3.1. sets a radius of curvature of not less than 2.5 mm for parts “in potential, static contact with a sphere”, with the devices “mounted in the position recommended by the manufacturer for normal driving”. Paragraph 16.2. now says “front or lateral side(s) view image” instead of “front and lateral side(s) view image” for the FLVCS default.

Activation
It shall be possible to easily activate the FLVCS and the detection system when the gear is in the out of parking out-of-parking or neutral range.
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Field of vision planes (para. 15.2.) and test object locations (Annex 9, para. 1.2.)

In paragraph 15.2., plane (a) “passing through a point 300 mm from the contour of the sides of the vehicle” is now a longitudinal vertical plane, not a transverse vertical plane. Plane (b) “passing through a point 300 mm from the contour of the front of the vehicle” is now a transverse vertical plane, not a transverse horizontal plane. Paragraph 15.2. now refers to new Figure 6, which replaces Figure 2. Annex 9, paragraph 1.2., has a rule for the vehicle equipped with CMS that comply with UN Regulation No. 46, 04 series of amendments. This rule now names the centres of Class III or II CMS camera lens, instead of Class II CMS camera lens. The Figure 2 “Test Object Locations” drawing in Annex 9 is changed and marks the “Centre of side mirror (UN-R46 class III or II)”.

The field of vision (see Figure 2 6 below) shall be bounded by the following planes:
A transverse longitudinal vertical plane passing through a point 300 mm from the contour of the sides of the vehicle;
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Means of vision and awareness (paras. 15.1. and 15.2.1.3. to 15.2.1.5.) and mirrors with several reflecting surfaces (para. 15.2.3.)

Paragraph 15.1. now includes “Via a combination of the means of vision and awareness, and declared by the manufacturer”. Paragraph 15.1. also contains the text on overlaps of designated areas and on the manufacturer’s declaration to the technical service. The examples of designated areas are now in Figure 5, instead of Figure 3. Paragraph 15.2.1.4., on a device of detection system, and paragraph 15.2.1.5., on a combination of the means in paragraphs 15.2.1.1 to 15.2.1.4., are deleted. In paragraph 15.2.3., former 15.2.6., the words “and have the dimensions specified for the class to which they belong” are deleted.

Via a combination of the means of vision and awareness, and declared by the manufacturer.
Overlaps of designated areas by different means (see examples in Figure 35) shall be permitted.
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Ambinocular vision figure (para. 12.2.) and adjusted ocular points of Annex 10 (paras. 15.2.1. and 15.2.2. and Annex 10)

In paragraph 12.2., “Ambinocular vision” now refers to Figure 4, which has a direct vision case and an indirect vision case. Under paragraph 15.2.1., the test object must be revealed in the Annex 9 test “using ambinocular vision from the adjusted driver's ocular points, or binocular vision from the adjusted ocular reference point calculated by the methods described in Annex 10”. The adjusted driver's ocular points calculated by the methods described in Annex 10 do not apply to devices using monitors. Paragraph 15.2.2., former 15.2.5., now also refers to Annex 10, and cites UN Regulation No. 43, 01 series of amendments, instead of the 04 series. Annex 10, paragraphs 1. to 3., no longer start with “In testing according to paragraph 15.2.1.1.”, and the heading of paragraph 2. adds “front and”.

"Ambinocular vision" means the total field of vision obtained by the superimposition of the monocular fields of the right eye and the left eye (see Figure 1 4 below).
Figure 4
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Transitional provisions for the 01 series of amendments (paras. 23. to 23.7.)

From the official entry into force of the 01 series, Contracting Parties applying this Regulation must not refuse to grant or accept its approvals (23.1.). As from 1 September 2026, they are not obliged to accept type approvals to the preceding series first issued after 1 September 2026 (23.2.). Until 1 September 2027, they must accept type approvals to the preceding series first issued before 1 September 2026 (23.3.). As from 1 September 2027, they are not obliged to accept type approvals issued to the preceding series (23.4.). Under paragraph 23.5., they must continue to accept preceding-series approvals “for the vehicles and devices for means of front and lateral vision which are not affected by the changes introduced by the 01 series of amendments”. They may grant type approvals, and must continue to grant extensions of existing approvals, to any preceding series (23.6. and 23.7.).

Transitional provisions
As from the official date of entry into force of the 01 series of amendments to this Regulation, no Contracting Party applying this Regulation shall refuse to grant or refuse to accept type approvals under this Regulation as amended by the 01 series of amendments.
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Scope, approval numbers, approval mark, Chapter 20 title and references (paras. 1.1.2., 1.1.3., 5.2., 5.4.1., 14.2. and 20., Annexes 5, 8 and 9)

In paragraph 1.1.3., approvals at the request of the manufacturer for other categories are now under Part II, instead of Parts I and II. Paragraphs 5.2. and 14.2. now say an approval number is assigned to each approved type in accordance with Schedule 4 of the Agreement (E/ECE/TRANS/505/Rev.3). In Annex 5, the approval mark example now gives UN Regulation No. 166 and approval number 012439, instead of No. xxx and 002439. The title of Chapter 20 now reads “Penalties for Non-Conformity of Production”, not “Penalties for Non-Conformity of Protection”. A new footnote to paragraph 1.1.2., the footnote to paragraph 5.4.1. and Annex 9, paragraph 1.3.3.2., now cite R.E.3 document ECE/TRANS/WP.29/78/Rev.7. A new footnote in Annex 8 says that the procedure is described in Addendum 6 of Mutual Resolution No. 1 (M.R.1).

At the request of the manufacturer, Contracting Parties may grant approvals under Parts I and Part II to vehicles, and to the installation of devices for fitting to such vehicles, of other categories and devices for fitting to such vehicles.
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Q2Why it changed

Proposed by
Expert from Japan and expert from the Netherlands
Working party
GRSG, 127th session (April 2024)

Reasons

  • The proposal adds impact safety requirements for mirrors, copied from UN Regulation No. 46, which reflects the latest amendment (GRSG-126-24r1). It exempts the devices approved by UN Regulation No. 26 or No. 61. Annex 13 also reflects the latest amendment of UN Regulation No. 46.

    Sources (2)
    “The addition of impact safety requirements for mirrors copied from UN Regulation No.46 which reflects the latest amendment (GRSG-126-24r1) and exempt the devices approved by UN Regulation No. 26 or No. 61.”
    “Reflects the latest amendment of UN Regulation No. 46 (GRSG-126-24r1).”
  • The proposal adds impact safety requirements for FLVCS and detection systems, the same as for mirrors (paragraph 6.1.3.).

    Source
    “Addition of impact safety requirements for FLVCS and Detection system same as mirror (6.1.3.).”
  • The text was reorganized between paragraphs 15.1. and 15.2. for clear descriptions. The figures on pole location at the centre of the side mirror were updated to avoid misinterpretation.

    Sources (2)
    “Reorganized between two paragraphs 15.1 and 15.2 for misunderstanding and for clear descriptions.”
    “The figures on pole location at the centre of the side mirror were updated to avoid misinterpretation.”
  • A description of the driver’s ocular point adjustment in Annex 10 was added for clarification, and sentences were removed from Annex 10 for clarification. The proposal also says that the reference for the series of Regulation No. 43 is corrected.

    Sources (3)
    “Add description about the driver’s ocular point adjustment in Annex 10 for clarification.”
    “And, the reference for series of Regulation No.43 is corrected.”
    “Remove sentences for clarification”
  • The description of the approval number in paragraphs 5.2. and 14.2. was harmonized with the 1958 Agreement, Rev.3.

    Source
    “The description of approval number harmonized with the 1958 Agreement, Rev.3.”

Document trail

  1. 2024-01ProposalECE/TRANS/WP.29/GRSG/2024/12Proposal for the 01 series of amendments by the expert from Japan
  2. 2024-01ProposalECE/TRANS/WP.29/GRSG/2024/25Proposal by the expert from the Netherlands to update the references to the 3-D H-point measurement and calibration procedure
  3. —RevisedGRSG-127-11-Rev.1Amendments to ECE/TRANS/WP.29/GRSG/2024/12 by the expert from Japan
  4. —Amended in sessionGRSG-127-19Amendments to ECE/TRANS/WP.29/GRSG/2024/25 by the expert from the Netherlands
  5. —Working party adoptsECE/TRANS/WP.29/GRSG/106Session report, paras. 16 and 17
  6. 2024-08Sent to WP.29ECE/TRANS/WP.29/2024/98Text that GRSG sent to WP.29 and AC.1
  7. —Amended in sessionGRSG-128-01-Rev.1Corrections to ECE/TRANS/WP.29/2024/98 by the experts of Japan
  8. —Working party adoptsECE/TRANS/WP.29/GRSG/107Session report, para. 14 (corrections adopted)
  9. 2024-11WP.29 adoptsECE/TRANS/WP.29/1181Adopted at the 194th session (session report, para. 158)
  10. 2025-06-12In forceC.N.347.2025.TREATIES-XI.B.16.166UN depositary notification

Q3Who is affected

Vehicle manufacturer

  • Check the field of vision against the changed planes (a) and (b) and new Figure 6.
  • Check the field of vision with the adjusted driver's ocular points or ocular reference point of Annex 10. Do not use the Annex 10 adjusted driver's ocular points for devices using monitors.
  • Check devices other than mirrors against the protective housing requirements of paragraphs 15.4.3. to 15.4.3.6.
  • Note paragraph 23.2.: from 1 September 2026, preceding-series approvals first issued after that date need not be accepted.

Component supplier

  • Check that your mirrors meet the protective housing requirements of paragraphs 6.1.3. to 6.1.3.8.
  • Be ready for the paragraph 6.2. impact test of mirrors and, for exterior mirrors with a stem, the bending test.
  • Check that your devices other than mirrors meet paragraphs 15.4.3. to 15.4.3.6.

Technical service / Approval authority

  • If the reflecting surface edge is not enclosed by the protective housing, identify “the worst case test positions for both impact directions” with the manufacturer (6.2.2.2.2.2.).
  • In Annex 9 tests, use the adjusted driver's ocular points or ocular reference point calculated by the Annex 10 methods.
  • In Annex 9 tests, do not use the Annex 10 adjusted driver's ocular points for devices using monitors.
  • Be ready for type approvals under the 01 series from its official date of entry into force (23.1.).

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ⓘ This report gives advice only. It is not legal or type-approval advice.

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