The timing could hardly have been worse - the day when Zealandia was offering entry for only $2 was also the day roadworks were scheduled at the Karori Tunnel.
With the road down to one lane on the city side of the tunnel for resealing work, cars full of families were backed up as far as Kelburn Village.
"I'd avoid Karori if I were you," Cam Russell said on Twitter.
"Everyone's out and there [are] big roadworks by the tunnel. Stop/Go men galore."
Metlink said its bus routes 3 and 23 experienced significant delays.
Wellington City Council spokesman Richard MacLean apologised to all those held up in traffic, and said timing of the work would be reviewed.
"We will be doing that as a matter of priority."
The work was halted for a time yesterday afternoon to allow both lanes to open. Mr MacLean said the resealing should be completed overnight.
Zealandia spokesman Peter Laurenson said the timing seemed "odd" - "I don't think it was very helpful."
However, the gold-coin day had been a success, with more than 4000 people through the gates.
A car crash in Karori added to the delays. An 85-year-old man was treated by ambulance staff after his car left the road and ended in a garden near the entrance of Karori cemetery.
Traffic was also heavy in Newtown, as people tried to get to Wellington Zoo, which was also offering entry for a gold-coin donation as part of Wellington Open Day.
The zoo reported more than 6800 visitors yesterday.
- The Dominion Post
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