Kingsland-to-Britomart trains will use both lines to quickly clear Eden Park.
Auckland's trains will have a Rugby World Cup dress rehearsal during tomorrow night's Super 15 game.
New signalling will allow both lines out of Kingsland Station to carry trains towards Britomart for the first time to quickly clear Eden Park of rugby fans.
Auckland Transport says trains will be leaving both platforms in the same direction at five-minute intervals after the match between the Blues and Crusaders.
It expects rail operator Veolia to carry up to 9000 fans from Kingsland to Britomart, stopping only at Grafton, and leaving Morningside Station for about 1000 passengers travelling to western destinations.
The new arrangements follow major upgrades to tracks and signals ahead of September's tournament.
About 14,500 of 60,000 spectators at Rugby World Cup final matches are expected to catch trains from Kingsland, and 1500 from Morningside.
Auckland Transport, meanwhile, intends building a railway station at Parnell and lengthening Onehunga's under-sized platform in a fast-tracked programme to upgrade its regional network for electric trains.
The council-controlled organisation's board has supported in principle a $38.9 million plan to upgrade 21 stations in time for the commissioning of an electric rail fleet from 2013.
But it will need to secure funding from its Auckland Council parent and the Government's Transport Agency first.
Subject to funding, it hopes to extend the Onehunga platform by the end of July and to complete full upgrades of its Remuera and Penrose stations by October.
These will be followed closely by upgrades at Green Lane by the end of the year and Mt Albert by the following April.
The new Parnell station is expected by the end of July next year, and Newmarket's former heritage station building should be moved to the site in the following two months.
The overall cost is expected to be about $15 million, of which about $4.2 million remains from a $5 million budget inherited by KiwiRail from the former Labour Government for storing and relocating the 112-year-old Newmarket building.
Onehunga's platform will be lengthened by 20 metres to allow it to cope with three-car trains, after it was built in haste last year without consents needed for a longer structure.
Auckland Transport says patronage of about 850 passengers a day is better than expected and a new railway designation obtained by KiwiRail will allow it to build a longer platform.
Upgrade
* Trains will be able to leave in the same direction from both platforms at Kingsland Station after tomorrow night's Super 15 rugby match at Eden Park, as a dress rehearsal for Rugby World Cup crowds.
* Auckland Transport has approved in principle a $38.9 million upgrade programme for more than 20 other stations.
* Programme to include a new station for Parnell and a longer platform for Onehunga.