Key Points:

A new railway station is opening today at Auckland's Sylvia Park shopping centre, in time for school-holiday crowds.

Trains will stop at the new station at least once every 30 minutes - and more often at peak times - giving shoppers and retail workers a 19-minute ride from Britomart or a 31-minute trip from Papakura.

That compares with a 45-minute bus ride from central Auckland and an often-frustrating hunt for a vacant parking space for those who drive to Sylvia Park.

But passengers must make sure they board an eastern line service to reach the shopping centre, via the waterfront and Glen Innes, as the southern line bypasses it.

Although it looks similar to most other new stations being developed in Auckland's railway revival, it is unusual in that it was paid for by the shopping centre's developer.

But although that was a requirement of its resource consent, Kiwi Property Income Trust has gone further by supplying 200 free 10-trip train tickets to retail workers to introduce them to rail transport.

"We really want to encourage people to use the train," said chief executive Angus McNaughton, whose centre caused a traffic nightmare a year ago when cars blocked the Southern Motorway as shoppers chased bargains at the opening of Sylvia Park's first stage of 50 shops.

The centre now has 200 shops spread over 6.5ha, and has resource consents to start building office blocks.

Mr McNaughton said the property trust had been keen to build the station as soon as possible, but had to wait to fit in with the regional transport planning considerations.

In other changes to suburban rail services, trains will run every 30 minutes - instead of hourly - between 9am and 3pm on Saturdays on the southern line through Newmarket and the eastern line through Glen Innes.

Peak-time services on week days between Henderson and Britomart will be doubled to four an hour.

But trains throughout the network will leave each station seven or eight minutes earlier on Saturdays than they do now, and passengers should also look out for minor timetable variations on weekdays.