Part 1: What’s The Big Difference? EDR v. Data Logger v. “VPD”
EDRs—or “Event Data Recorders”—were “first introduced by General Motors in basic form on air-bag-equipped models in the mid-1970s;” by 2005, they were in use “in 64 percent of all new models.” Consumer Reports, “Black box 101: Understanding event data recorders” (2014). Readers may think of EDRs as the “black boxes” in vehicles that investigators pull and analyze following a crash event. This is fundamentally true. In fact, in 2006, NHTSA established a regulation to “help ensure that EDRs record, in a readily usable manner, data valuable for effective crash investigations and for analysis of safety equipment performance (e.g., advanced restraint systems).” 49 CFR § 563.1 et seq. (2006). But EDRs have limitations. Most significantly, an EDR only records data in a crash (or crash-like) event, and even then provides only a snapshot of the seconds leading up to the event. EDR information also can be unreliable. For example, an EDR may fail to record an entire crash event, may be incorrectly calibrated, or may be destroyed in a crash event. For more detail on these limitations, we suggest reading here and here.
”Data logger” is a term embodied in new standards introduced by SAE for “common data output formats and definitions for a variety of data elements that may be useful for analyzing the performance of automated driving system (ADS) during an event that meets the [specified] trigger threshold criteria.” In essence, a data logger is an enhanced EDR for vehicles with Levels 3, 4, or 5 automated features (although the SAE standard envisions that data logger will be used in conjunction with EDR).