Veolia says it has "sold" only 77 such fares since the penalty was almost doubled a month ago from $10.30.
One official observing the blockade said it was likely others without tickets decided to stay on trains until the next stop after seeing so many red-jackets in waiting, but Veolia managing director Terry Scott said ticket inspectors were boarding about one in every three trains.
"We are showing the people of Auckland we are serious about protecting our revenue," said Mr Scott.
"While by far the majority of our passengers are doing the right thing, there is still a small percentage who think they have the right to travel on our trains without paying, and it's really annoying the people who are doing the right thing."
Auckland Transport operations chief Greg Edmonds said fare evasion - which he calls theft against the public purse - was still running at about 7 per cent of all patronage at an annual cost of "probably six or seven million dollars".
He hoped a bill before Parliament would be passed by July to allow inspectors to impose fines of about $150, although a figure has not been attached to the legislation.
Although blockades of stations began more than a fortnight ago, Mr Edmonds said they were initially trial runs of barricades to ensure honest customers were not held up in queues, and it was only this week that they started with "intensity".
They would continue across all stations until Veolia had enough data to build profiles of which ones were at greatest risk from fare evasion, for longer-term attention.
Middlemore Hospital human resources manager Allison Enright, a rail user with a Hop card, said movement through the station had improved since initial delays while "loads of kids" were caught.
Fare cheating
$20 Penalty fare for not having a valid ticket
$150 Suggested fine once new legislation passes
7% Estimated level of fare evasion
55 ticket inspectors across the network