Interesting. There was an example of 12.2.1 potentially getting confused by US 101 signs from almost a month ago, but seems to be common enough in California to know not to set the speed limit to 101. It seemed to have been confused by a passing vehicle blocking the right side of the sign resulting in 10 MPH speed limit:On US 15 in PA/MD most of the time it would set the speed limit to 15 MPH when it passed a US 15 sign
I suppose extra caution for those using 12.x on US highways that might end with a "0" or "5" (potentially when partially blocked).