The Transport Agency has revealed a 140-million dollar plan to speed up trips to and from Auckland Airport.

It's accelerating a plan already on the books to turn George Bolt Memorial Drive into a full motorway - hoping to complete the project by early 2017.

A trench would be dug to carry airport traffic under busy Kirkbride Road in Mangere, and it would be turned into a full motorway interchange.

At the moment a set of traffic lights causes a sudden halt to speeding traffic there, and four fatal crashes have resulted since 2004.

The project would be completed about the same time as the Waterview connection, which will mean faster trips from downtown Auckland.