[SPDSHDW]

It’s probably scanning for signs, if it has Adaptive cruise control.
Modern cars have all sorts of sensors, cameras, and other nonsense. Most of this required by law. Joepedo’s NTHSA is forcing cars to detect speed limits and cut your speed if you’re 10 over posted speed limit. This is to go into effect by 2028. This is probably a lighter version of that.

There is also the possibility it’s getting the local speed limit via LTE telematics, based on GPS data, but I cannot say for sure.

[bert]

The future is now