WP.29 adopts amendments to UN Regulation 171 (DCAS) — a shared EU gateway

The UN Economic Commission for Europe's World Forum for Harmonization of Vehicle Regulations (WP.29) advanced work on UN Regulation No. 171, which governs Driver Control Assistance Systems (DCAS). Regulation No. 171 itself was adopted by WP.29 in March 2024 and entered into force on 30 September 2024. It defines DCAS as systems that assist the driver in controlling the longitudinal and lateral motion of the vehicle on a sustained basis without taking over the entire driving task, and it classifies them as SAE Level 2. The regulation explicitly requires warning strategies for cases where the system detects a lack of driver engagement, so that the driver remains attentive and ready to intervene.

Subsequent work has proceeded within the Working Party on Automated and Connected Vehicles (GRVA). GRVA adopted the draft 02 series of amendments to Regulation No. 171 and forwarded it to WP.29 and AC.1 for consideration and a vote. The vote was scheduled for the June 2026 session, with the 02 series moving through the forum as document WP.29/2026/86. The amendments refine the requirements for monitoring driver engagement and set out conditions for operation on highway-like roads.

Regulation No. 171 operates under the 1958 Agreement, to which dozens of contracting parties, including the European Union, have acceded. That means a type approval issued on the basis of the harmonized UN text is recognized by other parties to the Agreement. For FSD (Supervised), the significance of this framework is that national regulators in EU countries rely on the common UN text when assessing and recognizing type approval of Level 2 systems. The adoption or amendment of Regulation No. 171 does not by itself mean that a specific feature is approved in any given country: approval is granted separately by a national authority on the basis of the technical documentation.