The Government's choice for a second Waitemata Harbour crossing is being called 'comical'.

It includes two three-lane tunnels for vehicles and a 21 kilometre light rail tunnel between Albany and the CBD.

It'll take decades to finish and cost tens of billions of dollars.

Greater Auckland director Matt Lowrie disapproves of the high cost and projected emissions, and says there are better uses for $40 billion.

"Proper public transport to the Northwest, out East, to the airport and Botany, round Upper Harbour- there are plenty of places where we could spend $40 billion to vastly improve transport all around Auckland."

LISTEN ABOVE

• "Failed to cooperate": Wayne Brown on the proposal for a second Harbour Crossing
• Sir John Key on the proposal for a second harbour crossing after a decade
• 'No question' second Auckland crossing needed- PM