Rail to Auckland Airport is going back to the drawing board as transport planners consider trams as a cheaper option.
Auckland Transport is under pressure to safeguard a rail route from Onehunga to the airport before the NZ Transport Agency builds a $140 million motorway extension along George Bolt Drive - some of it in a trench below Kirkbride Rd in Mangere - from early next year to 2017.
Electric trains were the preferred option of a multi-agency group led by the council body in 2011, after Auckland Mayor Len Brown promised airport rail by 2020 in his first Super City election campaign.
It was to be his second transport priority after the $2.4 billion rail loop under central Auckland. But airport rail slipped down the list in 2012, in favour of a new road link from Onehunga to East Tamaki, and 2030 was reset as the target for a $1.18 billion loop through both Onehunga and Manukau.
The cost estimate has since ballooned to $1.63 billion for just one link by 2045 as an extension of the Onehunga railway line. Even that depends on alternative revenue such as motorway tolls or higher fuel taxes and rates being provided to fill a $12 billion transport funding gap.