****** offences

[montydog]

is parking on broken double yellow lines in an unadopted road illegal

[dzug]

It's illegal (probably the wrong word) to use an unadopted road at all without the express or implied permission of the road owner.

Their remedies if you ignore this are a bit limited though.

[montydog]

in more detail, a ticket has been issued to a vehicle parked on yellow lines that are incomplete, and on an unadopted road, highways department say they have the right to enforce restrictions on any road used by the public.
is there a way of getting out of the parking fine?

[monkeyeyes]

The fact that the yellow lines are incomplete makes them 'unenforceable'.

Take a photograph of the break and send it to the issung authority.