Hi Andy, in general these paths aren't separated physically with barriers or grass.
It looks like this path:
https://upload.wikimedia.org/wikipedia/commons/thumb/8/84/Witosa_bike_2.jpg/400px-Witosa_bike_2.jpg
I can tak some photos on Monday, but stretch from Górnicza to Nowowiczlińska doesn't even have a different color of sidewalk on the border of sidewalk and bicycle path.
We has a discussion about paths like this and most of mappers prefer 1 lane with proper tags. There was even local discussion about paths in Tricity.