>>1979950oic is german (whole EU prob as well)
it gets writen onto a black box in the truck and police will read it when they pull a truck over,
Its more about road safety, not having tired drivers, like poor guys from east europe that have been driving for 12 hours straight without break or sleep, the blue segment is break time for example, so drivers are required to pull over at the next truck stop and do a break there or they get a fine.
back in the day it was a paper disk now its digital, and it also writes the driven speed.
