As the question list ECE/TRANS/WP.29/2012/35 did not lead to the respective answers in WP.29 the document was withdrawn and replaced by an interim report on the future approach to be presented to WP.29 in its 159th session. Section 0 contains the management summary, while the rest of the text gives more explanation.

The working group discussed the proposal in depth and amended it, resulting in document DETA-17-03-rev.1 or informal document WP.29-159-21.