There are limits on the weight of vehicles on New Zealand roads and bridges. These limits were introduced to protect roads from overloading.

General access mass limits

Historically most roads have been maintained to a level called 'Class 1' (also referred to as 'Class I'). More recently, the term Class 1 has been replaced with the term 'General Access'.  General Access has the same mass limits as Class 1, except that slightly increased gross masses are allowed on long vehicles. The General Access mass limits can be found in the Vehicle Dimensions and Mass Rule(external link).

Bridges with speed or weight restrictions below the General Access limits are called 'Posted bridges'. These restrictions are used where necessary to protect them from damage through over-loading. This also helps to keep road users safe. 

Posted bridges 

Bridges are commonly posted because of deteriorating condition, damage caused by illegal overloading, or where they were originally designed for lower load limits than current General Access limits.  Bridge postings can be applied for short periods to enable repairs or strengthening to be completed, or for long periods of time where the bridge still meets the current needs of the network. 

A list of Waka Kotahi posted bridges can be found further down this page. This list is reviewed in October each year, though additional postings may be added during the year as required.

Posted bridge restrictions are legally enforceable limits covered by regulation 11(external link) of the Heavy Motor Vehicle Regulations 1974.

Speed restrictions

Speed restrictions are the most common form of restriction. Lowering the speed of travel reduces the dynamic effects of the vehicle on the bridge as it crosses. Some bridges require restrictions on both speed and weight.

Where road users exceed the bridge speed and weight limits, they cause damage to the structure and also put themselves and others at risk. This can lead to the closure of a bridge to keep all road users safe.

Changes to the way bridge postings are presented

Waka Kotahi NZ Transport Agency is changing the way bridge restrictions are presented. This is to make them more easily understood.

Until recently, bridge restrictions may include one or more of the following;

  • Speed of travel over a bridge
  • Individual axle weights
  • Gross mass of the vehicle, expressed as a percentage of the Class 1 limits.

Road users have often found it difficult to understand the “gross mass limit”. To determine their vehicles mass limits users needed to look up the axle set and gross mass limits within the Vehicle Dimensions and Mass Rule.

The new method of presenting this information will enable road users to quickly understand their maximum load limits. Under the new approach, bridges can be posted with

  • Speed of travel over a bridge
  • Individual axle and axle set weight limits
  • Gross mass limits, which vary depending on how many axles a vehicle has.

The table below provides an example of the different limits for a typical posted bridge.

Name of road

Name of bridge

Mass limits

Maximum speed limit (km/h)

Maximum mass on any 1 axle

Gross mass (maximum sum of axle mass)

State highway

Bridge name

Single: N/A

2 axles: 8T

3 axles: 11T

50

Tandem: 7.5T

4 axles: 13T

5 axles: 16T

Tri: 9T

6 axles: 18T

7 axles: 20T

Quad: 10T

8 axles: 22T

9 axles: 25T

Under the previous approach, the posting included in the table above would have been presented as '50% of Class 1, 50km/hr'.

Bridge posting limits will vary depending on the reason for the restriction. Some bridges will require only speed restrictions, whereas others may also require restrictions on axle masses or the gross mass of the vehicle.

In time, all postings on the state highway and local road networks will be changed to this new approach.

Notification of weight and/or speed limits on state highway bridges 2023-24

Waka Kotahi has fixed the following maximum weight and/or speed limits for heavy motor vehicles and combinations that include a heavy motor vehicle on the bridges below (bold restrictions indicate changes made since October 2022):

Region

Name of road

Name of bridge

Route position (RP)

Mass limits

Maximum speed limit (km/h)

Maximum mass on any 1 axle

Gross mass (maximum sum of axle mass)

Northland SH14 Tangiteroria Bridge 30/0.24 -   30
Northland SH14 Awakino River Bridge No. 132 44/10.49 -   30

Northland

SH15

Awarua River Bridge

27/3.53

-

-

10

Waikato

SH3

Ōtorohanga Rail Overbridge

36/19.27

-

44,000kg

-

Waikato SH25 Waikawau River Bridge 42/13.36     10

Waikato

SH25

Grahams Stream Bridge

156/13.94

-

-

10

Waikato

SH25

Ramarama Stream Bridge

217/6.00

-

-

10

Waikato

over SH26

Flooks Stock Overbridge

80/7.92

-

44,000kg

10

Bay of Plenty SH2 Manganuku Bridge 345/6.03     30

Bay of Plenty

SH35

Raukokere River Bridge

94/0.00

-

-

10

Bay of Plenty

SH36

Ngongotaha Steam Bridge

28/17.8

-

44,000kg

-

Bay of Plenty

Ngamuwahine Road

Ngamuwahine Bridge

-

-

25,000kg

10

Gisborne

SH35

Hikuwai River No. 1 Bailey Bridge

250/6.22

-

-

10

Hawke’s Bay

SH2

Waikare River Bailey Bridge

577/14.62

-

-

10

Hawke’s Bay

SH50

Ngaruroro River Bridge (Fernhill)

17/0.0

-

2 axles: 11T

3 axles: 15T

30

4 axles: 18T

5 axles: 22T

6 axles: 25T

7 axles: 28T

8 axles: 31T

 

Canterbury

SH7A

Waiau Ferry Bridge

0/0.80

-

-

20

Canterbury

by SH 74

Tunnel Admin Access Bridge

-

-

40% Class 1

-

Canterbury

SH82

Elephant Hill Stream Bridge

32/0.00

-

-

30

West Coast

SH6

Waiho River Bailey Bridge

610/0.0

-

-

30

West Coast

SH6

Fox River Bridge

626/8.4

-

44,000kg

30

West Coast

SH6

Cook River (Weheka) Bridge

639/0.0

-

44,000kg

30

West Coast

SH6

Karangarua River Bridge

659/0.0

-

44,000kg

30

West Coast

SH6

Haast River Bridge

750/0.0

-

44,000kg

-

West Coast

SH7

Stoney Creek Bridge

212/0.0

-

-

30

Otago

SH6

Fish River Bridge

814/1.26

-

44,000kg

30

Otago

SH6

Camerons Creek Bridge

814/7.51

-

44,000kg

30

Otago

SH8A

Clutha River (Luggate) Bridge

15/3.8

-

-

30

The following bridges have further restrictions in place in accordance with New Zealand Transport Agency (Traffic Controls on State Highways) Bylaw 2017/14:

Region

Name of road

Name of bridge

RP

Bridge weight limit

Canterbury

SH7A

Waiau Ferry Bridge

0/0.80

One heavy vehicle on bridge

West Coast

SH6

Fox River Bridge

626/8.4

One heavy vehicle on bridge

West Coast

SH6

Cook River (Weheka) Bridge

639/0.0

One heavy vehicle on bridge

West Coast

SH6

Karangarua River Bridge

659/0.0

One heavy vehicle on bridge

Related information

Bridges and structures