While walking down the isles of various passenger car corridors between seats i have stepped onto a invisible box that lifts me upto or into the roof,now these boxes are not always in the same place and can change location depending on where your train is stopped? Note:I haven't seen this on all routes but it happens enough to get noticed.
These data recorders vary widely from manufacturer to manufacturer. They record a variety of different information, and their main purpose is to record delta velocity to allow your airbags to deploy more efficiently and save your ass when snaptube vidmate you crash.
