A lot of internet service providers were pushing fibre connections to increase speeds but there were still slowdowns in the international link.
Internet service providers oversubscribing their quota of the connection could cause a slowdown in internet speeds. That would usually occur around 3.30pm and then again between 5pm and 7pm when students and then workers arrived home.
It wasn't as much of an issue among smaller providers which dealt mainly with businesses, said Mr Prebensen.
The Chorus data showed average internet speeds increased from 16 to 26 megabytes per second (Mbps) over the 18 month period in Napier.
It increased from 14 to 22Mbps in Hastings and from 10 to 12Mbps in Central Hawke's Bay.
Mr Prebensen said speed would be an issue until everybody could access fibre connections.
Nationally, the average New Zealand home used 102GB of broadband data in June 2016 - more than double the amount used at the start of 2015 (49GB).
Chorus head of market insight Rosalie Nelson said more than half of New Zealanders now watched television and films online.
"But this isn't just about watching more and more content online, it's also about the rapid digitisation of our everyday lives."
Broadband sat at the heart of the home and played a pivotal role in how people function in their day-to-day lives, she said.
Typically, homes now had several connected devices at any one time and with the surge in data use, people expected and demanded faster and more reliable broadband speeds.
"With faster broadband, you don't have long delays while streaming or downloading high definition TV and video or face frustrating buffering - even when there are multiple connected devices in your home," said Ms Nelson.