The O-PBORoad(66).zip file only lists the road names and a picture showing the road piece.
But a clue to the road lengths are in the file names.
For example:
asf25.p3d.....is 25 metres long
asf12.p3d.....is 12.5 metres long
asf6.p3d.......is 6.25 metres long
The curved road pieces however are not as easy.
asf10 75.p3d for example means the road turns through 10 degrees and has a curved length of 75 metres......maybe.
Hope this helps.
Planck