Over the many years, the wind has done a number on that old sign. The neighbor about three miles north has an old tractor with steel wheels and steel chevrons welded on the rim. It has spoked wheels. One of these days I will stop and take a picture and post.
I still remember those signs on our highways. After WWII There were some tractors and implements that used the steel wheels, and the tractors and Caterpillars had the huge lugs that would destroy a highway. I recall seeing a spot where a steel lugged tractor had been driven across a blacktop. Our signs read: "Tractors with lugs prohibited". I think the signs were removed sometime in the 1960's.