problem in reading illuminated speed signs

[beewalker]

I find tesla always misread 80 as 60 on illuminated speed signs. Sometimes it somehow slows down though the highway is clear because of misread. Anyone has the same problem?

 

[ifung90]

i think the reading of the speed sign is GPS based more than "vision" based .. i will blame that as a fault in the GPS system recognizing the speed limit changes.

 

[Vmax]

Don't think it's GPS, but camera based. Yes beewalker, I made the same observation like you.

 

[Lerxt]

Yes, it is camera based and it struggles to read the illuminated signs.

 

[ediot]

i've set my speed limit reminder (at 10km/h excess of limit) to dashboard sign instead of the chime, since i notice it coming on more often than i'd like - i find that there're a few roads where the speed limit is 80 km/h (with those big red circle speed limit signs) and the car "reads" as 60km/h, hence thinking i'm over the limit. i usually drive at no more than 4km/h above the stated limits.

as for how the car determines the speed limit, i've read that the car first uses its cameras to try to read speed limit signs, and should that not be available/readable, it relies on GPS location vs its stored speed limit database. I'm not 100% on this as i cannot find official documentation from Tesla regarding this, but it seems like a reasonable way to do it - if any roads have construction work going on and a temporary speed limit sign is up, the car would ideally read and stick with that.