If you have ever been to Auckland you have certainly noticed how appalling the public transport system is in this town. If you have not, check my laments on the subject. It certainly is a major factor why I would rank Auckland lowly as a favourite city to live - please disregard surveys like this one because their information is aimed at expat workers who don't ever need to use public transport because they earn expat salaries.
For all other people, there is at the moment simply no rapid transit system anywhere in this city:
Buses have to share the road space with increasing traffic resulting in major delays and slow progress. Even bus lanes are haphazardly strewn around, mainly in the wrong places instead of on the major bus routes downtown.
Trains are of the toy town variety and belch their way through a few suburbs often on single tracks. Yes, diesel too. The Auckland Wellington railway has not been electrified even though electricity has been invented over a century ago.
There is no underground, trams or trolley buses.
Hell, there isn't even a public transport option to the airport, only private transport (including a rickety bus service). The major shareholders (including City Councils) of the Airport prefer to keep it that way because a large proportion of the Airport's income is derived from parking charges.
So with this array of opponents it's a wonder that any plans exist, let alone are being implemented, for an airport rail link. You can help things along with signing the Campaign for Better Transport petition.