So my parents did some road geeking for me and snapped this with a non-Apple cell phone (I forget which brand) and noticed some pixelation. Notice how the I-95 shield against the sky and lettering isn't smooth. You can also see it on the arrow and the "O" in "TO." Any idea what that is and can photoshop correct it?
(https://c1.staticflickr.com/1/509/18807252809_3d6d5987cf_b.jpg) (https://flic.kr/p/uDW62t)Old state-named I-95 shield. Commerce St. Springfield, VA. (https://flic.kr/p/uDW62t) by mergingtraffic (https://www.flickr.com/photos/98731835@N05/), on Flickr
Is the picture you've shared the actual resolution of the picture as it was taken? In other words, is there a larger size of the photograph out there?
One thing that came to my mind is the resolution of the picture that was sent. The original picture on the phone may be of better quality, but phones will downsize a picture to more easily and quickly send them using less data. Many pictures I've seen will be like 2 MB in full resolution, but I've seen pictures downsized to as low as 20 KB which results in a lack of quality. The size of your photograph is not that large and I think either a) the picture was downsized when it was sent or b) the setting in the camera phone needs to be bumped up. I went back and checked the resolution on a 4 year old Android phone I use to have and the resolution on it is 1840 x 3264 pixels which is well above the picture you have up. I'd say at most you are at half of that which will result in quality issues.
In terms of photoshopping the photo you currently have, from my experience, there's not much you can do. I'm afraid any doctoring would result in a lack of sharpness and make the picture blurry. Your best option would be to downsize the picture some to give the illusion that the photo is of a better quality. When I use to use point and shoot cameras, I would stick to 4 by 6 prints to increase the photo quality. I would try deceasing the resolution in photoshop to say 600 x 800. That's a total guess, but try some different options.
I think your best bet is to see if your parents have a better resolution (higher quality) version of that picture that they can send you. If not the best option is see if there's better settings on the camera phone and try taking the picture again if that's possible.