Supplement 1 to the original version of UN R151 (GRSG/2019/25) amended the paragraph 5.3.1.4. to add an explicit requirement for the maximum detection distance. The Supplement did not intend to delete or suggest a change in the requirements for the information signal boundaries or the detection area around the front wheel. This proposal reintroduces and clarifies the requirement for the detection area around the front wheel.
This proposal (WP.29/2021/102) was adopted by the World Forum. Forty Contracting Parties out of the 56 applying UN R151 were present for the vote by AC.1. Thirty-eight voted in favor with zero against and two abstaining.