Detail in-game is a little less than decent and ends up being kind of blurry. All corners seem to be cut off somehow, more so on the left and upper corners of the sign. The text color against the bright yellow sign makes it hard to read.
I've also seen this sign design used way to many times on this site.
Fix the corners so that they are not cut off abruptly.
Change text color to something more readable, or add a stroke around it.
The engineer is awfully blurry probably due to having to shrink him down to such a small size. You could create a silhouette in place of the fully colored/detailed version to make the image more crisp. I would also increase the size of him a bit to take up slightly more space on the sign.
Try a different sign design instead of this one which gets used a lot around here.