double yellow lines by law end at the hedgerow, so in essence if you drive over the dyl and park on the verge you are actually parking on double yellows. therefore a traffic wardens jurisdiction doesnt end at the kerbside.
i work for sussex police and wherever possible i try not to dish out parking tickets, problem is parking in sussex for the main is still governed by police officers unless the council decriminalise it (like in brighton and lewes). but i do let businesses park on dyl to do their job (especially window cleaners as i did used to be one).
however there are a few people that take the p%!s and block roads off or double park causing chaos. in this case i normally stand in front of the vehicle and write the ticket out. its amazing how quickly people move their vehicle then.
i will let you into one little tip though. im not sure about private traffice attendents but this is for police officers that might be booking you up.
if you get back to them while they are writing out the ticket, dont have a go, but just apologise and explain why you parked there. then ask if they would consider voiding the ticket this time. police can void the ticket at any time, even after its on the car. if people dont scream at me or call me names then i will invariably void the ticket. cant speak for every pc in the country though as there are some that enjoy giving out the tickets.