IMO, I would stay away from shots that most of the photographers have access to in the first place.
My understanding of the initial 3 images is to be "different", unique AND creative. If it has to be a shot of a traffic sign chose a different angle or do something creative in post processing. This image doesn't show skills.
White balance could also be an issue.
Put the sign in context to its proper meaning like here:
http://www.istockphoto.com/stock-photo-10221555-curves-ahead.php?st=915d13fYour image is a traffic sign showing a mountain in the background. This might work if the sign shows "curves ahead" or a warning sign for "wildlife crossing" something like that.
I hope this makes sense.