UN R79 — Supplement 8 to the 03 series of amendments

Paragraph 2.4.17., sub-paragraph (a), on the “Lane Change Manoeuvre”, now refers to the front wheel of the “power driven vehicle”. Sub-paragraph (b) now refers to the rear wheels of the “power driven vehicle (or combination)”. Before this supplement, both sub-paragraphs referred to the wheels of the vehicle. “Electric control line” (paragraph 2.7.) now means the electrical connection between two vehicles which provides the steering control function to a towed vehicle within a combination. Before this supplement, the definition said “to the trailer” and did not say “between two vehicles”. New paragraphs 2.8. and 2.9. define “Data communication” and “Point-to-point”.

Under paragraph 5.6.4., power-driven vehicles equipped with an ACSF of Category C and trailers supporting lane change function(s) must fulfil the relevant following requirements. New paragraph 5.6.4.8.1.1. covers power-driven vehicles able to assist lane change in solo condition, and trailers of Category O3 or O4 supporting lane change function(s). For trailers supporting lane change function, the detection area of paragraph 5.6.4.8.2. must be extended to the sides of the trailer including the coupling device. The calculation of the minimum operation speed Vsmin is now in new paragraph 5.6.4.8.1.4., the former paragraph 5.6.4.8.1. Paragraph 5.6.4.8.3. now refers to detection by the system of the power driven vehicle or the trailer (as relevant). Paragraph 5.6.4.8.4. now refers to blindness detected on the power-driven vehicle or on the trailer, as relevant.

New paragraphs 5.6.4.8.1.2. and 5.6.4.8.1.3. set requirements for N2 and N3 vehicles able to assist lane change when coupled to an O3 or O4 trailer. With a trailer supporting lane change functions, the detection area of paragraph 5.6.4.8.2. applies to the sides of the power-driven vehicle. The ACSF of Category C must be deactivated (off mode) if the coupled trailer does not fulfil paragraph 5.6.4.9., unless the vehicle meets paragraph 5.6.4.8.1.3. With a trailer not supporting lane change functions, the declared Srear (not less than 55 m) is specified from the trailer’s rearmost point. The manufacturer must also declare the maximum trailer length LT up to which the power-driven vehicle is able to perform a lane change manoeuvre. If the coupled trailer is longer than LT or its actual length is not available, the ACSF-C must be deactivated (off mode).

New paragraph 5.6.4.9. applies to vehicles implementing lane change function(s) based on trailers supporting lane change function(s). The data communication line must conform to ISO 11992-1:2019 and ISO 11992-3:2021 and be a point-to-point type. When a trailer is connected through electric control lines, the power-driven vehicle must detect a continuous line failure (> 40 ms) and warn the driver. With a coupled trailer, the GPM 11 message must be sent to the trailer, and the GPM 21 message received, before ACSF functionality is enabled. Under new paragraph 5.6.4.5.5.1., the system failure signal from a coupled O3 or O4 trailer supporting lane change function(s) must trigger the warning signal. Former paragraphs 5.6.4.9. and 5.6.4.10. are now paragraphs 5.6.4.10. and 5.6.4.11.

New paragraphs 7.3. to 7.3.3. in Annex 1 record (yes/no) the ACSF of Category C and the lane change cases of the power-driven vehicle. The cases are: solo condition, coupled to a trailer supporting lane change function(s), and coupled to a trailer without its support. New paragraph 8.4. in Annex 1 records (yes/no) whether the trailer is equipped with an ACSF of Category C supporting lane change function(s). Annex 8, paragraph 3.5., now says which tests apply to each case, with the trailer coupled during the test for the trailer cases. A trailer supporting lane change function must fulfil the tests of paragraphs 3.5.6. and 3.5.9. New paragraph 3.5.8. is a lane change suppression test, and new paragraph 3.5.9. is an object detection test for trailers supporting lane change function(s).

New Annex 9 covers the compatibility between towing vehicles and trailers with regard to data transmission according to ISO 11992 for environmental monitoring. Its requirements apply only to towing vehicles and trailers equipped with an electric control line as defined in paragraph 2.7. It lists the ISO 11992-3:2021 messages that the towing vehicle or trailer must support, as appropriate. New Annex 10 gives a procedure that may be used to check towing and towed vehicles equipped with an electric control line. The check is against the functional and performance requirements referred to in paragraph 5.6.4.1. Alternative procedures may be used at the discretion of the Technical Service if an equivalent level of checking integrity can be established.

Paragraph 5.3.3.1. now says “indefinitely” instead of “indefinitively”. In Annex 8, paragraph 3.5.4.1., test condition (f) now ends with “or 7.0 seconds if initiated by a second deliberate action”. New test condition (g) reads “The second deliberate action for an appropriate system is performed later than 5.0 seconds after the initiation of the lane change procedure”.