The previous session report was approved with a note on post-crash recording intervals. A DSSAD Guidance Document feedback deadline was set for month-end. Phase 2 discussions on near-miss events require clarification of concepts and their safety contributions. For EDR Step 2, a 10 Hz sampling rate was adopted over 2 Hz following opposition from industry regarding implementation burden and support from regulatory bodies for accident reconstruction needs. Outstanding discussion items will be consolidated into a working document. Terms of Reference discussions on maintaining current structure versus integrating DSSAD into the ADS Informal Working Group will continue. The May 12 meeting was rescheduled due to conflict with ESV Toronto.
The Subgroup on EDR held a conference call to discuss Event Data Recorder Step 2 specifications. Key discussions included: AEB trigger recording intervals, with agreement on -2.5 to 2.5 seconds; ADDW and DDAW data elements referred to GRSG with competing proposals in square brackets; DCAS data elements with unresolved differences between industry and UK proposals on recording intervals and frequency; time to collision (TTC) deferred to Step 3; engine throttle deletion deferred pending further consideration; transitional provisions with industry proposing 2031 implementation versus EC’s 2029; and EDR for ADS requiring further development. Memory definitions for R169 and R160 were agreed upon.
This document presents draft amendments to UN Regulation No. 169 for the EDR Step 2 workstream. It defines non-volatile memory as permanent EDR data storage retained after power loss, and volatile memory as temporary buffering that does not retain data. Requirements specify that EDRs capture and record data to non-volatile memory when triggered, with capacity for at least five events. Trigger conditions include sudden deceleration exceeding 3.25 m/s² for 0.7 seconds and vehicle stops at 0 km/h for 20 seconds. An amendment allows certain stop events to be recorded in volatile memory first, transferring to non-volatile memory when other triggers occur or the master switch deactivates, reducing memory wear in vehicles with frequent stops.