Re: What could this be?
Tyre... hmm... tyre track definitely not, but tyre... no, tyre neither. Only fooling you.

Webbing, straps, strings, coins, keys... what about these little things that can shine... it sounds like a wrong way also.
Car or house door... it could be... maybe... really?... but, sorry, it is not either.
Eh, Andy, you accidentally used the key word again... and I lost it again.
Maybe some hint could help. Let's try some EXIF info for starter:
Nikon D90, Nikkor 18-200mm, Exposure Time: 1/250, F-Number: 16.0, ISO: 200, 35mm Based Focal Length: 300, Focusing Distance: infinity
Peter
PS: Phil, thank you much for visiting my pages and liking a bit of them. That Vancouver summer holiday trip was fantastic and the city and its beautiful area is pinned as "to visit once again" on my traveler's map.