Teslas most certainly read speed limit signs. They have for years now. My stock Model Y purchased in January 2021 had the feature built-in. With FSD beta, turn

Teslas most certainly read speed limit signs. They have for years now. My stock Model Y purchased in January 2021 had the feature built-in. With FSD beta, turning off a major highway onto my neighborhood street (very narrow and no lane markings), it defaults to 25 MPH. About 100 feet later, the car sees the 35 MPH sign and speeds up accordingly. In this case, 35 MPH is too fast given the curves, slight hills, and limited visibility. I slow down manually in these cases using the roller wheels. Tesla has gradually improved its speed planning to account for different scenarios. But it's still a work in progress and often requires manual tweaking.