... I'm confused. How does any of this matter? Driver should still be aware enough to slow down if there's a temporary lower limit, but none of that affects that the car has enough to know that there's a maximum usual and customary speed limit, what it is, and programmatically CANNOT be set to exceed that usual and customary limit.Cars need to have cameras to detect and adjust. I find it takes about six months for Google Maps to update speed limit changes and temporary construction limits are almost never reflected. Also, I-70 through the Colorado Rockies has a variable speed limit depending on weather and road conditions. The speed limit signs are electronic and CDOT can and does change them as needed.