UN R13 Supplement 3 (15 series) · UNECE Regulation No. 13 (ECE R13) — Uniform provisions concerning the approval of vehicles of categories M, N and O with regard to braking.
UN R13 — Supplement 3 to the 15 series of amendments
Supplement 2 → 3
- What changed
- Vehicles of categories M2, M3 and N without manual braking controls for normal operation are no longer outside the scope (para. 1.2.5. deleted).
- Whilst an ADS feature is active, the warnings and other driver information of this Regulation must go to the ADS (para. 5.3.3.).
- New paragraphs 1.1.3. and 1.1.4. of Annex 4 set how to test vehicles of categories X and Y and other vehicles with an ADS.
- Why
- The TF on FADS prepared its amendments to enable the application of UN Regulation No. 13 to automated vehicles, including those without manual controls.
- The change to paragraph 5.3.3. aims to let the active ADS receive the warnings and fault signals that would otherwise go to the human driver.
- The proposal for paragraph 5.2.1.31. aimed to align UN Regulation No. 13 with provisions that GRVA had already approved for UN Regulation No. 13-H.
Q1What changed48 changes
Scope, braking controls, the driver and categories X and Y (paras 1.2.5., 2.3., 5.1.2.1. to 5.1.2.3., 5.2.1.2.1.)
Paragraph 1.2.5. is deleted, so this Regulation no longer excludes vehicles of categories M2, M3 and N without manual braking controls for normal operation. The definition of “braking system” (para. 2.3.) now says that the system consists of the control (if any), the transmission and the brake. In paragraphs 5.1.2.1. to 5.1.2.3., the sentence on braking from the driving seat now starts with “A driver, if any”, not “The driver”. For vehicles of categories X and Y, paragraph 5.2.1.2.1. no longer requires at least two controls that are independent of each other. Categories X and Y are also exempt, like M2 and M3, from the rule that a released brake control returns to the fully off position. The footnote on the Consolidated Resolution (R.E.3.) now cites document ECE/TRANS/WP.29/78/Rev.8 and has the wording of Annex VI of ECE/TRANS/WP.29/1192.
The ADS in the transmission, energy reserve and parking brake rules (paras 2.5., 5.2.1.2.7.2., 5.2.1.26.4., 5.2.1.26.5.)
The definition of “transmission” (para. 2.5.) now covers the components between the control and/or ADS (as applicable) and the brake. Paragraph 5.2.1.2.7.2. now says “controlled by the driver or the ADS” for the use of an energy reserve. In paragraph 5.2.1.26.4., the parking brake rule now starts “After the powertrain has been deactivated”, not after the ignition/start switch is switched off. For vehicles of category M, the 30-second condition for automatic application of the parking brake now also requires no input by the ADS. In paragraph 5.2.1.26.5., a parking brake request can now also come from the ADS.
Special provisions for vehicles with an ADS (paras 5.3., 5.3.3., 5.3.4.)
Paragraph 5.3. now applies to any vehicle with an Automated Driving System, without the former exception for Automated Lane Keeping Systems (UN Regulation No. 157). Whilst an ADS feature is active, the warnings and other driver information of this Regulation, including those from a trailer, must go to the ADS. Before, paragraph 5.3.3. required this for detected faults whilst the ADS was active. The manufacturer must document how existing detected faults reach the ADS before an ADS feature becomes active, with a demonstration under Annex 18. New paragraph 5.3.4. allows the braking controls and their transmission links to the brakes to be disabled or disconnected whilst an ADS feature is active. This is without prejudice to the requirements of other applicable regulations.
Braking tests for vehicles with an ADS (Annex 4, paras 1.1.3. and 1.1.4.)
New paragraph 1.1.3. of Annex 4 requires all tests and requirements of the annex for vehicles of categories X and Y. Without manual driving controls, the braking tests must use a dedicated activation method. The manufacturer must demonstrate that this method accurately replicates ADS braking performance. The test report must describe the method and record the braking demand with the results of each test. For other vehicles with an ADS, new paragraph 1.1.4. requires the tests at least in the manual driving mode. ADS-mode tests are not necessary if the manufacturer demonstrates the same braking performance with ADS braking demands, but the technical service can request a test.
Vehicle stability function and control demand by the ADS (para. 2.34.2.1., Annexes 19 and 21)
The definition of “directional control” (para. 2.34.2.1.) now refers to the driver or the ADS. For directional control, Annex 21 now refers to the vehicle behaviour demanded by the driver or the ADS (as applicable). Annex 21 and Annex 19 now refer to control demand by the driver or the ADS (as applicable). In Annex 21, item (d) now reads “When it has been automatically or manually disabled, or disabled by an ADS”. Annex 21, paragraph 2.1.1., now refers to the definition in paragraph 2.34., not 2.4.
Warnings and signals that go to the ADS (Annex 21)
In Annex 21, a new sentence requires that, while an ADS feature is active, the signal is transmitted to the ADS. Whilst an ADS feature is active, interventions can be transmitted to the ADS in place of the flashing warning to the driver (para. 2.1.4.). If an ADS feature is active, interventions by related systems, for example traction control, can also be transmitted to the ADS. A failure or defect can be transmitted to the ADS (as applicable) in place of the optical warning to the driver (para. 2.1.5.). With an active ADS feature, the optical warning to the driver is not required, and the warning signal must go to the ADS. The sentence on interventions of the vehicle stability function used in any learning process is deleted.
Emergency braking signal and other wording changes (paras 5.1.4.7., 5.2.1.31., 5.2.2.24.6.3., Annex 22)
This supplement adds the words “regardless of its means of activation” to paragraph 5.2.1.31. on the emergency braking signal. An example of a means of activation is an auxiliary control as specified in paragraph 5.2.1.2.4. In paragraph 5.1.4.7., the status check now applies to “those electronic systems which have control over braking”, without the word “complex”. Paragraph 5.2.2.24.6.3. only adds the words “paragraph” and “specified” to two references. In Annex 22, paragraph 3.6., the handbook must include a warning about the consequences of not checking the automated connector compatibility. The marking must now be visible to “a user”, not “the driver”, when standing on the ground beside the vehicle.
Q2Why it changed
- Proposed by
- Task force on regulatory fitness for Automated Driving Systems (TF on FADS); for paragraph 5.2.1.31., experts from OICA and CLEPA
- Working party
- GRVA, 23rd session (September 2025) and 24th session (January 2026)
Reasons
WP.29 invited the working parties to start work on amending the regulations that the expert groups on regulatory fitness for automated vehicles identified. The TF on FADS prepared its amendments to enable the application of UN Regulation No. 13 to automated vehicles, including those without manual controls.
Sources (2)
“WP.29 endorsed the report (ECE/TRANS/WP.29/2023/86) transmitted by the expert groups on regulatory fitness for automated vehicles and invited the GRs to start the work on amending the regulations identified by the expert groups in the report.”
“The text reproduced below was prepared by the experts from the Task Force (TF) on regulatory Fitness for ADS (FADS) to introduce amendments to enable the application of UN Regulation No. 13 to automated vehicles, including those without manual controls.”
The proposal is to include vehicles that have no manual braking controls intended for use during normal operation. This aims at safety and uniformity in approval processes for all types of passenger cars, including ADS-equipped vehicles. Clear guidance on test requirements was considered necessary for ADS-equipped vehicles without manual controls (categories X or Y) and for those with manual driving modes. The guidance aims to make sure that all vehicle types in this Regulation can be fairly assessed and type-approved under the same framework.
Sources (3)
“To ensure safety and uniformity in approval processes for all types of passenger cars, including ADS equipped vehicles, it is proposed to include vehicles, which are not equipped with manual braking controls intended for use during normal operation.”
“It has been deemed necessary to provide clear guidance on testing requirements for ADS equipped vehicles, including those without manual controls (Category X or Y) and those equipped with ADS but still having manual driving modes”
“This aims to ensure that all types of vehicles covered by this regulation can be fairly assessed and type-approved under the same regulatory framework.”
In vehicles of categories X or Y, a warning strategy for the driver might no longer be essential. The change to paragraph 5.3.3. aims to make sure that the active ADS can receive and process critical vehicle information. This information includes the warnings and fault signals that would otherwise go to the human driver.
Sources (2)
“Where in the current vehicles categories, a driver-oriented warning strategy is essential, in a vehicle of Categories X or Y, it might not be the case anymore.”
“The proposed amendment to the existing paragraph 5.3.3. aim to ensure that the ADS, when active, can appropriately receive and process critical vehicle information, specifically warnings and fault signals that would otherwise be directed to the human driver.”
The proposal for paragraph 5.2.1.31. aimed to align UN Regulation No. 13 with provisions that GRVA had already approved for UN Regulation No. 13-H (ECE/TRANS/WP.29/GRVA/2025/45/Rev.1). An auxiliary control can be an Electronic Parking Brake (EPB) control, on a vehicle with an electronic parking brake system. It is common practice to apply the service braking system through the EPB control. The proposal aimed to clarify the existing text. The aim was an aligned and consistent interpretation of the activation conditions for the Emergency Stop Signal (ESS). This means that the application of the service braking system through the EPB control can generate the ESS.
Sources (5)
“The representative of OICA presented GRVA-24-08 proposing to align the provisions of UN Regulation No. 13 with those already approved by GRVA (ECE/TRANS/WP.29/GRVA/2025/45/Rev.1) for UN Regulation No. 13-H.”
“by means of an auxiliary control, which could be an Electronic Parking Brake (EPB) control in case of an electronic parking brake system”
“Therefore, the application of the service braking system via the EPB control is common practice.”
“The proposal aims to clarify the existing text in order to ensure an aligned and consistent interpretation of the activation conditions for an Emergency Stop Signal (ESS)”
“means the ESS can be generated by application of the service braking system via the EPB control”
Proposer's reason (informal document GRVA-23-14)
In the first phase of the TF on FADS work, ALKS vehicles were left out of the special requirements for vehicles with an ADS. The aim was to make sure that the amendments to UN Regulation No. 13 did not affect existing ALKS vehicles. The need for this exclusion was to be kept under review. The task force could not identify any provision in paragraph 5.3. that ALKS vehicles should not already have to meet under UN Regulation No. 157. Therefore, the proposal was to remove this reference and to treat ALKS vehicles like any other ADS vehicles.
Submitted by the co-chair of TF FADS. Working party adoption: ECE/TRANS/WP.29/GRVA/23, para. 23.
Sources (3)
“ALKS vehicles were omitted from the "special requirements for vehicles equipped with an ADS" to ensure that the amendments to UN Regulation No. 13 would not impact existing ALKS vehicles.”
“the Task Force has not been able to identify any provision within paragraph 5.3. that ALKS vehicles should not already have to meet according to the requirements of UN Regulation No. 157.”
“Therefore, it is proposed to remove this reference and treat ALKS vehicles like any other ADS vehicles.”
Document trail
- 2025-07ProposalECE/TRANS/WP.29/GRVA/2025/39Proposal by the TF on FADS
- —Amended in sessionGRVA-23-14TF on FADS changes for the 23rd GRVA session
- —Working party adoptsECE/TRANS/WP.29/GRVA/23GRVA session report, para. 23
- —ProposalGRVA-24-08Proposal by experts from OICA and CLEPA for paragraph 5.2.1.31.
- —Working party adoptsECE/TRANS/WP.29/GRVA/24GRVA session report, para. 77
- 2026-04Sent to WP.29ECE/TRANS/WP.29/2026/7/Rev.1Revised text that GRVA sent to WP.29 and AC.1
- —Amended in sessionWP.29-199-10Amendments for the AC.1 vote, reproduced in Annex VI of ECE/TRANS/WP.29/1192
- 2026-06-24WP.29 adoptsECE/TRANS/WP.29/1192Adopted at the 199th session (session report, para. 103)
- PendingIn forceDate not yet known
Q3Who is affected
Vehicle manufacturer
- For categories X and Y without manual driving controls, prepare a dedicated activation method for the Annex 4 braking tests. Demonstrate that the method accurately replicates ADS braking performance.
- For other vehicles with an ADS, test at least in the manual driving mode (Annex 4, para. 1.1.4.). If you do not test in ADS mode, show the technical service the same braking performance with ADS braking demands.
- Make sure that warnings and other driver information go to the ADS whilst an ADS feature is active (para. 5.3.3.). Document how existing detected faults reach the ADS before an ADS feature becomes active. Demonstrate this in accordance with Annex 18.
- If a vehicle has an Automated Lane Keeping System, check its braking system against the special ADS provisions.
- Make sure that the vehicle stability function can transmit its intervention and failure signals to the ADS (Annex 21).
- Check that the 30-second automatic parking brake rule for category M also takes input by the ADS into account.
- Make sure only service braking, whatever its means of activation, generates the emergency braking signal under paragraph 5.2.1.31. conditions.
Component supplier
- Make sure that your braking control units can send warnings and failure status to the ADS (para. 5.3.3.).
- Make sure that your stability control software uses control demand by the driver or the ADS (Annex 21).
- Make sure that your parking brake system meets paragraph 5.2.1.26.5. also for requests generated by the ADS.
- Give the vehicle manufacturer the data for the Annex 18 documents on fault transmission to the ADS.
- If your Electronic Parking Brake (EPB) control applies the service braking system, test the emergency braking signal with it.
Technical service / Approval authority
- Agree any activation method other than a test mode with the manufacturer (Annex 4, para. 1.1.3.).
- Make sure that the test report describes the activation method and records the braking demand for each test.
- For other vehicles with an ADS, decide whether to request an ADS-mode test of the braking performance (para. 1.1.4.).
- Check the Annex 18 demonstration of how existing detected faults reach the ADS before activation of an ADS feature.
- When you assess the emergency braking signal, include service braking through an auxiliary control (paragraph 5.2.1.2.4.).
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