The agency sent out another media release this afternoon asking motorists to allow extra time if travelling over the Kaimai Range this weekend.
Contractors are carrying out major road works that involves rehabilitating a 1120m stretch of SH29 near Soldiers Road and the Te Ahara bridge, the statement said.
The work started on March 30 and will be done in three stages. It is expected to be complete in late May.
The first 350m stretch of road being worked on is too narrow to keep two lanes open, so stop/go traffic management and speed restrictions of 30km/h are necessary.
The Transport Agency's Bay of Plenty Journey Manager, Nigel D'Ath said contractors were doing everything they could to reduce delays for motorists however due to the scale of the work people should allow an extra 20 minutes when travelling on the route.
He said contractors would be closely monitoring queues after motorists experienced significant delays when travelling through the site yesterday.
"The Transport Agency and its contractors plan ahead and work hard to ensure delays are kept to a minimum when carrying out work on New Zealand roads," he said.
"We get it right 95 per cent of the time but yesterday's delays were in the five per cent category.
"Traffic volumes were much higher than expected and motorists experienced unacceptable delays of up to 49 minutes when travelling westbound and 36 minutes eastbound, according to traffic monitoring technology.
"We apologise to people caught up in the queues."
Contractors are back working at the site today, however stop/ go will be kept to a minimum and queues will be closely monitored to avoid a repeat of yesterday's congestion.
The length of work site under the 30km/h speed restriction has been reduced to the legal minimum allowable and this should help traffic throughput through the site.
Contractors will be carrying out work today and over the weekend to prepare to seal the 350m stretch of road on Monday April 20 (weather permitting).
This type of work involves heavy machinery, loose metal, hot bitumen and a lot of workers, often on foot - that's why speed restrictions are needed.
Mr D'Ath said the sealing work on Monday will require one lane to be closed.
Stop/go traffic management and a 30km/h speed restriction will be in place and motorists are advised to plan ahead for delays of approximately 20 minutes or more, and consider using an alternative route such as SH2 via Waihi.
Work on the next two stages of rehabilitation along the length of the passing lane will follow that. Two lanes will be available to motorists during the final two stages of the road rehabilitation work and consequently delays should be shorter.
Mr D'Ath said it was critical that motorists slow down and keep to the speed limit through the work site.
"This type of work involves heavy machinery, loose metal, hot bitumen and a lot of workers, often on foot - that's why speed restrictions are needed," he says.
"Speeding through the sites can be dangerous for our road workers and other motorists, as well as causing damage to the work."
"We hope the travelling public understand the importance of these works and we thank them for their patience."
For real time information on highway conditions and incidents visit www.nzta.govt.nz call 0800 4 HIGHWAYS or follow @nztawaibop on twitter.
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