Weight restriction signs delayed for two west Waikato bridges


Waka Kotahi NZ Transport Agency advises two state highway bridges in west Waikato that will introduce new weight restrictions for heavy vehicles from 1 November 2021 will not have advisory signs installed in time for that date.

The Kopaki rail overbridge on State Highway 30 will be restricted to vehicles under 6 tonnes and the Mangaotama Stream bridge on State Highway 39 will be restricted to vehicles that are less than 50 per cent of Class 1.

Due to manufacturing delays, the signs are not expected to be installed until at least 15 November. Regardless of the manufacturing delay, drivers are asked to comply with the new weight limits, which are intended to keep both bridges safe for all traffic that use them.

The exact weight in tonnes of the Mangaotama restriction will vary between vehicles, depending on size and axle configuration, refer to the table below. This bridge needs a new bridge deck and supporting beams and Waka Kotahi has provisional approval for funding to carry out this work. Further details will be made available once funding and timing for this project has been confirmed.

The recommended detour for vehicles over 50 per cent of Class 1 travelling between Otorohanga and north of Hamilton is State Highway 3 and State Highway 1 through Te Awamutu and Hamilton.

A detour is available at the bridge for local heavy traffic using Meadway Road, Hams Road, Forkert Road and Ngahinapouri Road. This detour is not advised for through traffic as it is narrow with single lane bridges.

The timber Kopaki rail overbridge, about 23 km south of Te Kuiti on SH30, is currently restricted to 80 per cent of Class 1. However a further restriction is required to ensure it can remain open to light traffic while the replacement bridge is under construction. The new bridge, which will be able to be used by all heavy traffic, will be complete in 2023.

Trucks travelling between Te Kuiti and Maniaiti/Benneydale will need to use the existing heavy traffic bypass of State Highway 4 and Kopaki Road.

Waka Kotahi apologises for any inconvenience this may cause.

Name of Road

Name of bridge

Gross mass limit (maximum sum of axle mass)

Maximum speed limit (km/h)


Kopaki Rail Overbridge




Mangaotama Stream Bridge

2 axles: 8T

3 axles: 11T


4 axles: 13T

5 axles: 16T

6 axles: 18T

7 axles: 20T

8 axles: 22T

9 axles: 25T