What can you tell me about push bikes?

[rustyrobot]

The legal definition of a bicycle is .. a vehicle.

I'm not sure about that. The Land Transport Act appears to disagree. Perhaps our learned friend Mr HenryDorsetCase esquire would be able to weigh in on this.

Part 6
Driving offences involving drink or drugs, and penalties and procedures
Offences and penalties
56Contravention of specified breath or blood-alcohol limit
(1)A person commits an offence if the person drives or attempts to drive a motor vehicle on a road while the proportion of alcohol in the person's breath, as ascertained by an evidential breath test subsequently undergone by the person under section 69, exceeds 400 micrograms of alcohol per litre of breath.

Part 1
Preliminary provisions
2 Interpretation

motor vehicle—
(a)means a vehicle drawn or propelled by mechanical power; and
(b)includes a trailer; but
(c)does not include—
(i)a vehicle running on rails; or
(ii)[Repealed]
(iii)a trailer (other than a trailer designed solely for the carriage of goods) that is designed and used exclusively as part of the armament of the New Zealand Defence Force; or
(iv)a trailer running on 1 wheel and designed exclusively as a speed measuring device or for testing the wear of vehicle tyres; or
(v)a vehicle designed for amusement purposes and used exclusively within a place of recreation, amusement, or entertainment to which the public does not have access with motor vehicles; or
(vi)a pedestrian-controlled machine; or
(vii)a vehicle that the Agency has declared under section 168A is not a motor vehicle; or
(viii)a mobility device

[neels]

(viii)a mobility device

Mobility scooters for getting home from the pub when too pissed to drive

There are other laws they could get you on related to being intoxicated if they wanted I guess..