Nav/Traffic symbol question
 

Does anyone know what the following symbol represents on the nav screen with traffic info ?
It looks like two letter "A"s super imposed on each other in black with a thin white outline. There is also a small number in a circle on the top "A". Seems to appear near overpasses. In the small circle I have seen the number 3 and 5.
Have found nothing on it in the manual. These symbols come and go from time to time. Thought it represented an accident but I have never seen an accident near the symbol.

Could you get an image (photo) of what you're referring to - it owuld be easier to understand

Thanks

That would be difficult for me to do as these appear only occasionally and when they do I am driving.