Motorists travelling via State Highway 29 are being warned to expect delays.

Waka Kotahi Transport Agency is asking people to reduce speeds as emergency culvert repair work is carried out.

"Traffic is down to one eastbound and one westbound lane and a 50km/h speed restriction is in place near the Kaimai summit where the repair work is being carried out," says a spokesperson for the roading agency.

"Drivers are asked to reduce their speeds and plan for delays.

"The restrictions are expected to be in place over a couple of days while contractors establish the extent of the culvert dislodgement and blockages.

"Motorists are encouraged to check the Waka Kotahi Journey Planner site for traffic updates.

"Waka Kotahi thanks everyone for their patience and will provide further updates as soon as possible."

Plan ahead for a safe, enjoyable journey. Keep up to date with:

• Traffic updates: journeys.nzta.govt.nz/traffic

• Facebook: facebook.com/NZTAWaikatoBoP
• Twitter: twitter.com/WakaKotahiWaiBP
• Journey planner: journeys.nzta.govt.nz
• Phone: 0800 4 HIGHWAYS (0800 44 44 49)