Wellington public transport operators will have to front up to the regional council over poorly-planned bus replacements for the Kapiti commuter train.
Buses replacing trains on the Kapiti line earlier this week, while Kiwirail carried out annual work on the tracks.
But one commuter said she waited an hour and a half before being able to get on a bus on Tuesday.
She reported the bus was soon overloaded to the extent it was scraping the ground after picking up more passengers near Paekakariki.
Wellington Regional Council spokesperson Barbara Donaldson said that was unacceptable.
"We will be looking into that with Transdev who is our operator to find out exactly what happened and what went wrong so certainly we will be following that up."
Ms Donaldson said this year's bus plans were based off what happened last year, when the tracks were closed for maintenance.
Buses will continue to replace trains from Waikanae to Porirua until 3 January.