Eilidh Cairns verdict

I don't follow, carriageways are the actual road widths and therefore applicable to vehicle restrictions (like low bridges etc) Traffic lanes are whats left over if road works, bike lanes, obsticals etc are in the way?
or am i getting the wrong stick altogether?

Sort of. The street or road comprises the carriageway and possibly the footway. Both carriageway and footway can additionally be divided up into lanes (e.g., a cycle track or path on a footway, or several traffic lanes, perhaps a bus lane and two general traffic lanes, in the carriageway).