Auckland Transport is blaming last year's Rugby World Cup for recent falls public transport patronage, particularly on trains.
The council body says a 0.5 per cent fall in overall public transport trips last month compared with August last year - and a 4.4 per cent decline in rail patronage - was because of unfavourable comparisons with extra activity in the lead-up to the rugby festival.
It says that without the inflated patronage at that time, last month's rail patronage would have been 7.5 per cent higher than for the previous August and there would have been 5.7 per cent more public transport trips in general.
Northern Express services along the busway also suffered a patronage drop, of 2.5 per cent, although other buses carried 0.1 per cent more passengers and there were 3.6 per cent more ferry rides taken this August.
Public transport patronage for the 12 months to the end of August increased by 7.3 per cent to 71.6 million boardings of buses, trains and ferries.
A monthly report to Auckland Transport's board says the decline in rail patronage can be attributed mainly to the relative number of trips recorded on special event trains, early rugby-related promotions and extra tourism activity leading to the cup kick-off on September 9 last year.
But Auckland Council transport chairman Mike Lee is unconvinced.
"Auckland Transport's problem is that they claimed credit and included free Rugby World Cup [rail] trips in their totals and put out press releases saying how good they were doing with public transport," he said.
"Now that they haven't maintained that momentum for a number of reasons, not just because of the Rugby World Cup, they are now blaming the Rugby World Cup."
Despite the slowdown, Auckland Council has reported that almost as many people took public transport as those who used private vehicles to reach the central city in a two-hour morning travel peak on March 27, during its annual passenger survey.
Of 67,203 people who arrived in downtown Auckland between 7am and 9am, 33,484 (49.8 per cent) took public transport and 33,719 (50.2 per cent) came in private vehicles.
That represents a major shift from 2001, when just 36 per cent of 60,420 people came by public transport and only 718 (1.2 per cent) arrived by train.
Buses brought 23.717 (35 per cent) of people to the central business district during the latest survey, compared with 6055 (9 per cent) who arrived on trains and 3712 (5.5 per cent) on ferries.