Ask Phoebe: One line or two, same give-way rules apply

Is there a difference between who has to give way at a give-way sign that has double lines as opposed to a single white line?

I recently discussed with my dad a give-way scenario which then turned into a conversation about the white marked line(s) at a give-way sign. He's adamant there is a difference between who has to give way at a give-way sign that has double lines as opposed to a single white line. For example, two cars approach give-way signs opposite each other at an intersection. One car (blue, say) wants to turn left into traffic and the other (red) wants to turn right into traffic. The red car must give way to the blue.

However, my dad's understanding is that if the blue car is at a double-lined give-way road marking and the red car is at a single-lined give-way road marking, the blue car has to give way to the red car instead, as the double line marking denotes them having to give way to two flows of traffic. Is this correct?

I recall reading something years ago in the road code about the give-way road markings but cannot remember if this is the rule. My brother does not think this is true and if it is, then it is probably not common knowledge to the majority of drivers out there.
Vimara Chang, Auckland

I must say that this is a theory that has never come my way before, and I rather like its logic and simplicity.

However, it is completely wrong. Sorry, dad. There is no difference in law between one white line at a give-way sign, and two. The only difference is one of economy. It's cheaper to paint one line than two.

Can you tell me who is responsible for enforcing the ramp and signal restrictions at motorway on-ramps?

At the Papakura northbound on-ramp there is a reserved lane for trucks and cars with two or more people. During peak hours it is a joke. Cars with only one person use the reserved lane at the rate of several per minute.

I have never seen any enforcement of the signals or the reserved lane. I have emailed several agencies and received no response.
Robin Paterson, Papakura.

The police are responsible for enforcing speed limits on motorway on-ramps, as part of their regular motorway patrols. They are also responsible for enforcing any restrictions in priority lanes, such as trucks only or passenger numbers (T2 or T3 or more).

Ramp signals are operated by the Transport Agency from the NZTA/Auckland Transport Joint Transport Operations Centre at Takapuna.

The system is designed to help keep motorway traffic flowing as freely as possible. Electronic sensors measure traffic volumes and the signals turn on when the system detects congestion. Signals may operate because of congestion around just one ramp, but they may also regulate the number of vehicles joining a relatively clear section of motorway because the sensors have detected congestion further along the network.