Land Transport Rule

Setting of Speed Limits 2003

Rule 54001

Note: This Rule should be read in conjunction with Land Transport Rule: Setting of Speed Limits Amendment 2005 and Land Transport Rule: Setting of Speed Limits Amendment 2006.

Contents

Objective of the rule

Extent of consultation

Part 1     Rule requirements

Section 1     Application

Section 2     General requirements

Section 3     Review and setting of permanent and holiday speed limits and review and designating of urban traffic areas

Section 4     Permanent speed limits for roads in designated locations

Section 5     Temporary speed limits

Section 6     Variable and minimum speed limits

Section 7     Consultation, decision-making procedures, registration and recording of speed limits

Section 8     Signs and road markings

Section 9     Responsibilities, functions and powers

Section 10     Transitional provisions for designating urban traffic areas and validating saved speed limits

Part 2     Definitions

Schedule 1     Speed Limits New Zealand

 

Objective of the rule

In 1995, the Government decided that a land transport rule should be made for the setting of speed limits. The rule was intended to address deficiencies in the existing system that resulted from the complex mix of procedures and structures for setting speed limits. These led to the situation where the responsibility for, and ownership of, speed limits was divided between organisations at both central and local government level.

Land Transport Rule: Setting of Speed Limits 2003 establishes procedures whereby road controlling authorities may set enforceable speed limits on roads within their jurisdictions. The purpose of the procedures is to ensure that the risk to public safety is minimised and that the freedom of road users to travel on New Zealand roads at speeds that are reasonable and appropriate is protected through checks and balances on the actions of road controlling authorities. This is achieved through the Director of Land Transport Safety setting standards and auditing and monitoring the application of the rule by road controlling authorities. The power to set a speed limit is limited to road controlling authorities that have power to make bylaws concerning the use of roads under the Local Government Act 2002 (principally, territorial local authorities and Transit New Zealand); or power to make bylaws under specific legislation (such as some airport authorities).

The objective of the rule is to contribute to a safe and efficient road network by:

Prior to consultation on the rule, an industry working group was established to review speed limits policy and the method specified to calculate the appropriate speed limit for a given road. The working group’s recommendations were published in February 1995 as RTS 17: Guidelines for Setting Speed Limits. The guidelines have been used by road controlling authorities and the LTSA since then to set speed limits and are incorporated into the rule as Speed Limits New Zealand. Under the rule, road controlling authorities must apply this method to calculate speed limits either by following the instructions in Speed Limits New Zealand or by entering the data into a custom designed computer program.

It is important to note that the rule changes the procedure under which a speed limit is created, but it does not change the policy and method that dictate the choice of speed limit itself.

Extent of consultation

The consultation process for the proposed rule began formally in January 1997 when the LTSA released the preliminary (red) draft of the rule. The draft rule and disks containing a copy of Speed Limits New Zealand in the form of a computer program were sent to 135 organisations and individuals who had either registered an interest in the rule or who were considered likely to be interested in the rule. They included the country’s road controlling authorities (mainly, territorial authorities), the Police, Transit New Zealand, Transfund New Zealand, traffic engineering and transportation organisations, and the New Zealand Automobile Association. The LTSA received 34 submissions on the red draft.

The ensuing yellow draft of the rule, which included modifications made as a result of comments received on the red draft, was released for public consultation in December 1997. The availability of the yellow draft rule was publicised in metropolitan and regional newspapers, the New Zealand Gazette and Te Maori News. The draft rule was sent also to overseas libraries and transport organisations. Forty-seven submissions were received on the yellow draft. Further refinement of the rule followed as a result of this consultation.

Finalisation of the rule was delayed by the need for the LTSA, the Ministry of Transport and the Police to resolve a number of policy issues. Progress on the rule was also affected by the passage of the Land Transport Act 1998, which changed the legislative provisions concerning the matters a land transport rule could cover in respect of speed limits.

In March 2002, the LTSA sent a green draft of the rule to all road controlling authorities and groups and individuals who had made submissions on the yellow draft, for their final comments. The purpose of the green draft was to summarise the development of the rule to date, to discuss major issues the proposed rule sought to address and to set out areas where the LTSA sought further information and reaction to help in finalising the rule. Speed Limits New Zealand was included as a schedule to the draft rule. Forty-six groups and individuals responded to the green draft.

As a result of these responses, minor changes were made in redrafting the proposed rule before it was submitted to Cabinet, and to the Minister of Transport for signature.

 

Part 1     Rule requirements

Section 1     Application

1.1     Title of the rule

This rule is Land Transport Rule: Setting of Speed Limits 2003.

1.2     Scope of the rule

This rule:

1.3     Date when rule comes into force

This rule comes into force on a date to be notified in the Gazette by the Minister in accordance with section 160(3) of the Land Transport Act 1998.

 

Section 2     General requirements

2.1     Categories of speed limit

This rule provides for the following categories of speed
limit:

 

2.2     Range of speed limits

A speed limit that is set in accordance with this rule must be one of the following:

 

2.3     Urban and rural speed limits

2.3(1)     The urban speed limit is 50 km/h.

2.3(2)     The rural speed limit is 100 km/h.

2.3(3)     Except when a different speed limit is set under this rule or by or under any other enactment:

 

2.4     Road lengths for speed limits

2.4(1)     A road for which a speed limit is set under this rule must:

 

Table 2.1     Road lengths for speed limits

Speed limit (km/h) Minimum length (m)
50 500
60 500
70 500
80 800
100 2000

 

2.4(2)     In addition to applying to the road for which it has been calculated, a speed limit may apply to short lengths of road adjoining that road, even though those short lengths of road would not comply with Table 2.1.

2.4(3)     The point at which a speed limit changes must be at, or close to, a point of significant change in the roadside development or the road environment.

 

2.5     Traffic control devices

Before a speed limit comes into force on a road, a road controlling authority must ensure that all traffic control devices installed on the road are safe, effective and appropriate for the speed limit and comply with requirements for traffic control devices in the Traffic Regulations 1976 or a land transport rule that replaces the relevant provisions of the Traffic Regulations 1976.

 

2.6     Role of road controlling authorities in reviewing and setting speed limits

A road controlling authority, for roads under its jurisdiction:

 

2.7     Role of Director in changing and approving speed limits

The Director may:

 

2.8     When a speed limit is set, approved or changed and when it comes into force

2.8(1)     Except for a temporary speed limit, a speed limit is set by a road controlling authority when it makes a bylaw setting a speed limit or designating an urban traffic area.

2.8(2)     Except for a temporary speed limit, a speed limit that is set by a road controlling authority comes into force on the date specified in the bylaw that sets the speed limit.

2.8(3)     A speed limit is approved or changed by the Director when the Director declares the speed limit by notice in the Gazette.

2.8(4)     A speed limit that is approved or changed by the Director comes into force on the date specified in the Gazette notice that approves or changes the speed limit.

 

Section 3     Review and setting of permanent and holiday speed limits and review and designating of urban traffic areas

3.1     Calculation of speed limits

A road controlling authority must apply Speed Limits New Zealand to determine the calculated speed limit when reviewing or setting a permanent or holiday speed limit and when reviewing or designating an urban traffic area, unless the relevant road is in a location to which section 4 applies, in which case a road controlling authority may apply Speed Limits New Zealand.

 

3.2     Procedures for reviewing and proposing to set speed limits

    Permanent and holiday speed limits

3.2(1)     A road controlling authority must review a permanent or holiday speed limit, or propose to set a new speed limit, by determining:

3.2(2)     Unless section 4 applies, and subject to 3.2(5), if the calculated speed limit is the same as the existing speed limit, the road controlling authority must retain the existing speed limit.

3.2(3)     Unless section 4 applies, and subject to 3.2(5), if the calculated speed limit differs from the existing speed limit, the road controlling authority must propose to set the calculated speed limit in accordance with section 7.

 

Urban traffic areas

3.2(4)     A road controlling authority must review an urban traffic area or propose to designate a new urban traffic area by:

 

Speed limits that differ from the calculated speed limit

3.2(5)     A road controlling authority may propose to set a speed limit that differs from the calculated speed limit, but may set the proposed speed limit, in accordance with section 7, only if:

 

Speed limits less than 50 km/h

3.2(6)     A road controlling authority may propose to set a speed limit of less than 50 km/h but, unless section 4 applies, may only set the proposed speed limit if:

 

Obligation to review speed limits

3.2(7)     A road controlling authority must review a speed limit when:

 

Discretion to review speed limits

3.2(8)     A road controlling authority may review a speed limit if:

Transitional review requirements

3.2(9)     Before reviewing and changing a speed limit saved under section 4 of the Transport Amendment Act 1997, a road controlling authority must comply with section 10.

3.2(10)    A road controlling authority must, before 1 July 2005 or such later date on which section 52A of the Transport Act 1962 is repealed, in accordance with this section, review all speed limits that are limited speed zones and replace them with one of the speed limits in 2.2.

 

Section 4     Permanent speed limits for roads in designated locations

4.1     Setting a permanent speed limit for a road in a designated location

4.1(1)     A road controlling authority must comply with this section when setting a permanent speed limit for a road under its jurisdiction, in a designated location.

4.1(2)     A designated location is any of the following:

4.1(3)     A speed limit that is set in accordance with this section must be:

4.1(4)     A road controlling authority must, before setting a speed limit for a road in a designated location, consult with the Director, the Commissioner and other persons who the road controlling authority considers to be affected by the proposed speed limit and give them a reasonable time to make submissions on the proposal.

4.1(5)     A road controlling authority must set a speed limit for a road in a designated location by complying with the decision-making procedures and notification procedures, and recording the speed limit in a register of speed limits, in accordance with 7.2 and 7.3 respectively.

4.1(6)     Before reviewing and changing a speed limit saved under section 4 of the Transport Amendment Act 1997 for a road in a designated location, a road controlling authority must comply with section 10.

 

Section 5     Temporary speed limits

5.1     Setting a temporary speed limit

5.1(1)     A road controlling authority that is empowered by an enactment to make bylaws:

5.1(2)     A road controlling authority must consider the need to set a temporary speed limit and may set a temporary speed limit if it considers that:

5.1(3)     A temporary speed limit is set by installing signs in accordance with a traffic management plan approved in writing by the road controlling authority.

5.1(4)     A temporary speed limit:

5.1(5)     A person who is authorised to install a temporary speed limit sign in accordance with the traffic management plan in 5.1(3) may remove a temporary speed limit sign.

5.1(6)     A person in 5.1(5) must remove the temporary speed limit signs and equipment used to install or support the signs immediately there is no longer any need for the temporary speed limit.

5.1(7)     The Director or the Commissioner may, at any time, require the removal of a temporary speed limit and the removal of accompanying signs and equipment used to install or support the signs, if satisfied that:

 

5.2     Setting a temporary speed limit when there is a risk of danger

5.2(1)     A temporary speed limit that is set in accordance with 5.1(2)(a) must be safe and appropriate for:

5.2(2)     A temporary speed limit that is set in accordance with 5.1(2)(a) must be:

 

5.3     Setting a temporary speed limit for a special event

5.3(1)     A temporary speed limit that is set in accordance with 5.1(2)(b) for a special event must be safe and appropriate for:

5.3(2)     A temporary speed limit that is set in accordance with 5.1(2)(b) for a special event must be:

5.3(3)     A temporary speed limit that is set in accordance with 5.1(2)(b) for a special event may apply for:

 

Section 6     Variable and minimum speed limits

6.1     Variable speed limits

6.1(1)     The Director may, by notice in the Gazette and subject to any specified conditions that the Director considers appropriate, approve a variable speed limit.

6.1(2)     A variable speed limit relates to:

6.1(3)     A road controlling authority that is empowered by an enactment to make bylaws:

6.1(4)     The Director may, by notice in the Gazette, remove a variable speed limit.

 

6.2     Minimum speed limits

6.2(1)     The Director may, by notice in the Gazette and subject to any specified conditions that the Director considers appropriate, approve a minimum speed limit for a specified lane on a road, if that speed limit is safe and appropriate for:

6.2(2)     A road controlling authority that is empowered by an enactment to make bylaws:

6.2(3)     The Director may, by notice in the Gazette, remove a minimum speed limit.

 

Section 7     Consultation, decision-making procedures, registration and recording of speed limits

7.1     Consultation

7.1(1)     Before setting a speed limit, or designating or changing an urban traffic area, a road controlling authority must consult with persons that may be affected by the proposed speed limit, in accordance with this section, unless section 4, section 5 or section 10 applies.

7.1(2)     The persons that must be consulted in accordance with 7.1(1) are:

7.1(3)     A road controlling authority must consult by writing to the persons in 7.1(2) advising them of the proposed speed limit and giving them a reasonable time, which must be specified in the letter, to make submissions on the proposal.

Additional information to be provided for particular speed limits

7.1(4)     If a proposed speed limit is a holiday speed limit, the road controlling authority must write to those persons in 7.1(2) specifying the periods during which the proposed speed limit is to apply.

7.1(5)     If a proposed speed limit is to designate a new urban traffic area or change an existing urban traffic area, the road controlling authority must write to those persons in 7.1(2) specifying relevant details including:

7.1(6)     If a proposed speed limit is 50 km/h or more, and the proposed speed limit is not the calculated speed limit, the road controlling authority must provide the Director with written evidence that the proposed speed limit complies with 3.2(5), unless section 4 applies.

7.1(7)     A road controlling authority must provide the Director with any information requested by the Director that is relevant to a proposed speed limit of less than 50 km/h.

7.1(8)     When a road controlling authority proposes to set a speed limit under 7.2(1) by making a bylaw in accordance with any enactment, the consultation required by 7.1 may be carried out at the same time as, or as part of, any consultative procedure in that enactment.

 

7.2     Decision-making procedures and notification of set speed limits

7.2(1)     A road controlling authority that is empowered by an enactment to make bylaws must set a speed limit under this rule by making a bylaw in accordance with that enactment, unless section 5 applies.

7.2(2)     When deciding to set a speed limit, a road controlling authority must take account of submissions received during consultation on the proposed speed limit.

7.2(3)     Following review and consultation, if a road controlling authority decides the existing speed limit is not the safe and appropriate speed limit for a particular road, it must set a new speed limit.

7.2(4)     Except for a temporary speed limit, a road controlling authority must, at least 14 days before a speed limit comes into force, notify the Director and the Commissioner that a speed limit has been set and provide them, in writing, with the following information:

 

7.3     Registration of all speed limits except temporary speed limits

7.3(1)     A road controlling authority must establish and maintain a register of speed limits that records all speed limits, except temporary speed limits, for the roads under its jurisdiction, including:

7.3(2)     Information recorded in the register of speed limits must include:

7.3(3)     A road controlling authority must make the register of speed limits available for inspection by members of the public, at reasonable times, on request.

7.3(4)     Details of a speed limit that has been superseded by a new speed limit under this rule must be retained on the register of speed limits for at least seven years from the date on which the new speed limit came into force.

 

7.4     Records relating to setting of speed limits

When a road controlling authority sets a speed limit, other than a temporary speed limit, it must retain, for at least seven years from the date on which the new speed limit comes into force, data, correspondence, reports and other records relating to the review, consultation, decision-making procedures and setting of the speed limit, including records relating to the use of Speed Limits New Zealand.

Section 8     Signs and road markings

8.1     Requirement to provide signs

8.1(1)     Except as provided under 8.1(3), a road controlling authority must install a speed limit sign on the left-hand side of a road under its jurisdiction at or near, and not more than 20 m from, the point on the road where a speed limit changes.

8.1(2)     A road controlling authority must, in addition to 8.1(1), install:

8.1(3)     A speed limit sign may be installed otherwise than as required by 8.1(1) if authorised under this rule or other enactment, or when:

 

Table 8.1     Maximum length of road between repeater signs for permanent and holiday speed limits

Speed limit (km/h) Maximum length of road
between signs (km)
60 2.0
70 2.4
80 2.6

 

Table 8.2     Maximum length of road between repeater signs for temporary speed limits

Temporary speed limit (km/h) Maximum length of road
between signs (km)
20 0.7
30 1.0
40 1.4
50 1.7
60 2.0
70 2.4
80 2.6

 

8.2     Specifications for signs

The design, format, shape, colour and size of a speed limit sign must comply with requirements for signs in the Traffic Regulations 1976 or a land transport rule that replaces the relevant provisions of the Traffic Regulations 1976.

 

8.3     Specific requirements for permanent and holiday speed limit signs

8.3(1)     For a new permanent speed limit or a holiday speed limit, the speed limit shown on the associated signs installed by the road controlling authority must not be visible to road users until the speed limit comes into force.

8.3(2)     A road controlling authority must remove a sign for a holiday speed limit at the end of any period for which the holiday speed limit is in force.

8.3(3)     A road controlling authority does not have to comply with 8.1(2)(a) before 1 July 2005 or such later date on which section 52A of the Transport Act 1962 is repealed.

8.3(4)     A road controlling authority does not have to comply with 8.1(2)(b)(i) for a 70-km/h speed limit before 1 July 2005 or such later date on which section 52A of the Transport Act 1962 is repealed.

 

8.4     Specific requirements for signs for variable and minimum speed limits

8.4(1)     A road controlling authority, when setting a variable or minimum speed limit approved by the Director, must install signs as specified by the Director.

8.4(2)     For a new variable speed limit or minimum speed limit, the speed limit shown on the associated signs installed by the road controlling authority must not be visible to road users until the speed limit comes into force.

 

8.5     Road markings

A road controlling authority may, as specified in the Traffic Regulations 1976, or in a land transport rule that replaces the relevant provisions of the Traffic Regulations 1976, mark on the road surface alongside a speed limit sign the numerals shown on the speed limit sign.

 

Section 9     Responsibilities, functions and powers

9.1     Responsibilities of road controlling authorities

9.1(1)     A road controlling authority must comply with this rule when setting a speed limit.

9.1(2)     A road controlling authority must have audit processes to ensure quality control of its procedures for reviewing and setting speed limits.

9.1(3)     A road controlling authority must comply with directions given by, and requirements of, the Director under 9.2(2), 9.2(3), 9.2(6) or 9.2(7), and with requirements of the Commissioner under 9.3.

9.1(4)     A road controlling authority is liable for the expenses incurred by the Director under 9.2(4).

 

9.2     Functions and powers of the Director

9.2(1)     The Director may approve variable and minimum speed limits and change permanent, holiday, variable and minimum speed limits.

9.2(2)     The Director may audit road controlling authorities for compliance with this rule and may issue directions regarding matters to be addressed in the audit.

9.2(3)     If the Director considers that a road controlling authority has not complied with this rule in reviewing or setting a speed limit, or that a speed limit set by a road controlling authority does not comply with this rule, the Director may direct the road controlling authority to:

9.2(4)     If a road controlling authority does not comply with directions given under 9.2(3), the Director may exercise the appropriate responsibilities of a road controlling authority under this rule and change a speed limit, by notice in the Gazette.

9.2(5)     The Director may, for the purpose of section 4, approve a location other than one specified in 4.1(2)(a) to (m).

9.2(6)     The Director may, at any time, require the removal of a temporary speed limit and the removal of a speed limit sign and equipment used to install or support the sign under 5.1(7).

9.2(7)     The Director may direct a road controlling authority to install, modify or remove a speed limit sign to comply with this rule.

 

9.3    Powers of the Commissioner

The Commissioner may, at any time, require the removal of a temporary speed limit and removal of a speed limit sign and equipment used to install or support the sign under 5.1(7).

 

Section 10     Transitional provisions for designating urban traffic areas and validating saved speed limits

10.1     Designating urban traffic areas and validating saved speed limits

10.1(1)     A road controlling authority must designate an area in which roads are subject to a 50-km/h speed limit, saved under section 4 of the Transport Amendment Act 1997, as an urban traffic area.

10.1(2)     A road controlling authority must validate all speed limits saved under section 4 of the Transport Amendment Act 1997 other than:

10.1(3)     A road controlling authority must designate an urban traffic area in 10.1(1) or validate a saved speed limit in 10.1(2) by:

10.1(4)     When notifying the Director and the Commissioner, in accordance with 7.2(4), of a bylaw to designate an urban traffic area in 10.1(1) or to validate a saved speed limit in 10.1(2), a road controlling authority must provide the Director with the following information:

10.1(5)     If a speed limit saved under section 4 of the Transport Amendment Act 1997 applies to roads under the jurisdiction of more than one road controlling authority, each road controlling authority must designate an urban traffic area in 10.1(1) or validate a saved speed limit in 10.1(2) for only those roads under its jurisdiction.

10.1(6)     Before changing a speed limit saved under section 4 of the Transport Amendment Act 1997, a road controlling authority must:

10.1(7)     A road controlling authority must designate urban traffic areas in 10.1(1) and validate saved speed limits in 10.1(2) before 1 July 2005 or such later date on which section 52A of the Transport Act 1962 is repealed.

10.1(8)     Urban traffic areas in 10.1(1) and saved speed limits in 10.1(2) that have been designated or validated in accordance with 10.1(3) are considered to be set under this rule.

10.1(9)     Before 1 July 2005 or such later date on which section 52A of the Transport Act 1962 is repealed, a road controlling authority must record in the register of speed limits, in accordance with 7.3, urban traffic areas in 10.1(1), and saved speed limits in 10.1(2), that have been designated or validated in accordance with 10.1(3), but that have not been changed under this rule.

 

Part 2     Definitions

Calculated speed limit
means the speed limit calculated for a particular road by following the procedures set out in Speed Limits New Zealand.
Commissioner
means the Commissioner of Police.
Director
means the Director of Land Transport Safety appointed under section 186 of the Land Transport Act 1998.
Holiday speed limit
means a maximum speed limit set under this rule that is in force 24 hours a day for a specified period, or periods.
Limited speed zone
has the same meaning as in regulation 2 of the Traffic Regulations 1976.
Mean operating speed
means the mean of motor vehicle speeds measured on a dry road during mid-week, non-congested traffic flows.
Minimum speed limit
means the minimum speed set under this rule, at which a vehicle may legally be operated in a specified lane of a road.
Minister
means the Minister of Transport.
Permanent speed limit
means a maximum speed limit set under this rule, that is in force except when a holiday, variable, minimum or temporary speed limit is in force.
Register of speed limits
means the register established and maintained under 7.3.
Road
(a) includes:
  • (i) a street; and
  • (ii) a motorway; and
  • (iii) a beach; and
  • (iv) a place to which the public have access, whether as of right or not; and
  • (v) all bridges, culverts, ferries and fords forming part of a road or street or motorway, or a place referred to in (iv); and
  • (vi) all sites at which vehicles may be weighed for the purposes of the Land Transport Act 1998 or any other enactment; and
(b) includes a section of a road.
Road controlling authority
in relation to a road:
  • (a) means the authority, body or person having control of the road; and
  • (b) includes a person acting under and within the terms of a delegation or authorisation given by the controlling authority.
Rural area
means a road or a geographical area that is not an urban traffic area, to which the rural speed limit generally applies.
Rural speed limit
means a speed limit of 100 km/h.
(To) set a speed limit
means to establish or change a speed limit or to designate or change an urban traffic area under this rule or under an Act, regulation or bylaw before this rule came into force.
Special event
means an event held over a short and defined period which would involve a significantly different use of a road to the extent that the permanent speed limit or the prevailing holiday speed limit would not be safe.
Speed limit
means:
  • (a) the maximum speed at which a vehicle may legally be operated on a particular road, but does not mean the maximum permitted operating speed for classes or types of vehicle specified in any Act, regulation or rule;
  • (b) for a minimum speed limit, the minimum speed at which a vehicle may legally be operated in a specified lane of a road;
  • (c) an urban, rural, permanent, holiday, temporary, variable or minimum speed limit.
Speed Limits New Zealand
means the procedures for calculating speed limits set out in Schedule 1.
Temporary speed limit
means a speed limit that is in force for a period of less than six months and is set under this rule.
Territorial authority
has the same meaning as in section 5(1) of the Local Government Act 2002.
Urban speed limit
means a speed limit of 50 km/h.
Urban traffic area
means an area designated under this rule that consists of one or more specified roads or a specified geographical area, to which the urban speed limit generally applies.
Variable speed limit
means one of several preset alternative speed limits that may be in force for a particular road depending on the presence of specified conditions at that time, and that is set under this rule.

 

Schedule 1

Speed Limits New Zealand

Guidelines for setting speed limits and procedures for calculating speed limits

 

Contents

1.0     Introduction

2.0     Speed limits policy

3.0     Procedures for deciding on a speed limit

4.0     The decision-making process – calculating the speed limit

Glossary

Appendix I     Holiday speed limits

Appendix II     Survey forms

 

1.0     Introduction

Land Transport Rule: Setting of Speed Limits 2003 specifies the legal procedure for establishing speed limits on public roads. The rule incorporates Speed Limits New Zealand as the procedures for calculating the speed limit, and the Land Transport Safety Authority (LTSA) has developed a computer program to assist with this. Speed Limits New Zealand (SLNZ) supersedes RTS 17 Guidelines for Setting Speed Limits.

SLNZ specifies the procedures for calculating a permanent or holiday speed limit, and outlines the policy and principles on which the procedures are based. In the event of a contradiction between Part 1 of the rule and SLNZ, the provisions of Part 1 of the rule apply.

Instructions for installing and operating the computer program are included with the program.

 

1.1     Speed limits policy

The objective of speed limits policy is to balance the interests of mobility and safety by ensuring speed limits are safe, appropriate and credible for the level of roadside development and the category of road for which they are set. They must also be nationally consistent.

Road users are more likely to comply with a speed limit if it is consistent with limits on other roads in the network with similar characteristics, and if limits in general reflect the factors that most influence speed choice. The level of roadside development and the function of a road are the primary determinants of the appropriate speed limit. Consistency is an important aspect of road users’ perceptions of a reasonable speed limit and will influence their willingness to comply.

Although road geometry is also a factor in determining a speed limit, it is secondary to roadside development. In situations where the road geometry encourages road users to travel at a higher speed than the speed limit determined by roadside development, engineering techniques should be used to lower vehicle speeds. When a road in a built-up area primarily serves through traffic, engineering techniques and access controls should be used to provide safety at the higher speeds that will prevail.

 

1.2     Speed limits calculation

Historically, public road speed limits in New Zealand have been 50 km/h, for roads in urban situations and 100 km/h, for roads in rural areas and motorways. The rule does not change this general principle.

The general principle represents a balance between consistency and safety but, in some cases, the choice between 50 or 100 km/h does not allow the appropriate speed limit to be set for a particular section of road. The rule allows speed limits of 20, 30, 40, 60, 70 or 80 km/h to be set on roads where traffic patterns or road or land use make a speed limit other than 50 or 100 km/h appropriate and safe.

The rule requires road controlling authorities to use SLNZ to calculate the speed limit for any public road to ensure consistent application of speed limits policy across the public road network.

SLNZ sets out the method for calculating the speed limit for a section of road from the following information:

To review and set a speed limit under the rule, the road controlling authority must:

 

1.3     Speed Limits New Zealand (SLNZ)

SLNZ is the specified method for calculating a speed limit. The calculations can be done either manually, by following the procedures set out in this document, or by using the computer program. As well as calculating speed limits, the output of the computer program can be used to document the speed limit setting process and to maintain records of speed limits required by the rule.

The LTSA will maintain SLNZ to reflect changes in the rule that are brought about by changes in speed limits policy or that affect the method of calculating speed limits.

There will be some rare situations when, because of special features or activities along a road or route, SLNZ cannot be used or will not produce a sound result. SLNZ must always be used with reference to speed limits policy, and in conjunction with sound engineering judgement, to determine the appropriate and safe speed limit.

 

2.0     Speed limits policy

Under the rule, permanent and holiday speed limits may be 20, 30, 40, 50, 60, 70, 80 or 100 km/h. The policy for speed limits is set out below.

 

2.1     Urban speed limit (50 km/h)

The general urban speed limit is 50 km/h. In an urban traffic area, the urban speed limit indicates that drivers can expect to encounter vehicles that are turning, slowing, stopping or parking, pedestrians, cycles and heavy vehicles.

An urban traffic area is land close to or within a town or city. The land will generally appear fully built-up. Land uses include:

An urban traffic area also includes partly built-up areas:

Development on the land will generally be close to the roadside property boundary and there may be provision for parking and loading in front of commercial and industrial development. Sealed footpaths, kerb and channel, and landscaped grass areas between the kerb and the property boundary are typical of urban development. The roadside environment will be fully built-up, although access may be restricted.

Road geometry should not encourage higher speeds. Where road geometry tends to promote higher operating speeds than the level of roadside development warrants, engineering measures should be taken to increase the apparent activity on the road. These include narrowing of traffic lanes; marking cycle lanes and parking lanes; installing kerb extensions at pedestrian crossing points and installing roundabouts. Signal linking can also be used to discourage higher speeds.

 

2.2     Rural speed limit (100 km/h)

The general rural speed limit is 100 km/h.

A rural area is land outside towns and cities. The level of roadside development is at a minimum. Land use includes:

Houses in rural areas will generally be set back some distance from the road. There will be little kerbing and no footpaths unless installed for a specific reason (eg, a school remote from a residential area). Street lighting will generally not be provided but, if present, it will be only at specific community facilities or used as intersection indicator lighting.

In situations where the safe operating speed is below 100 km/h due to the road geometry or other limitations on the roadway, drivers should be made aware of the need to reduce speed. This can be achieved by means of warning signs, delineation and by the physical nature of the road itself. Using derestriction signs should also be considered as an alternative to using 100-km/h signs. It is not appropriate to install a lower speed limit.

 

2.3     Arterial route speed limits

Speed limits of 60 and 80 km/h are primarily intended as limits for arterial routes. A 50-, 70- or 100-km/h speed limit may also be appropriate on an arterial route in some circumstances.

The geometric features and general appearance of the road and surrounding development should be consistent along the entire length of the arterial route speed limit.

On a long route (more than 3 km), where the level of development on a short section (less than 1 km) varies from the predominant development along the route, it may be appropriate to install a constant speed limit over the entire route. In this situation it is essential that the specified geometric design criteria are complied with and that traffic responds safely to the posted limit, despite the variation in development.

The minimum recommended length of 1 km for 60- or 80- km/h speed limits on arterial routes, as specified in Table SLNZ1, emphasises that these limits are primarily intended for arterial routes that meet consistent standards over a reasonable length of road.

 

2.4     Speed limits of 20, 30 and 40 km/h

Speed limits of 20, 30 or 40 km/h may be set for local roads or minor collector roads in urban traffic areas where the road is used by motorised traffic and pedestrians or cyclists (eg, shared zones) and a speed limit less than 50 km/h is necessary for safety purposes. Speed limits of 20, 30 or 40 km/h are generally not suitable for roads serving a significant collector or arterial function.

These limits can only be set if the calculated speed limit for the road is 50 km/h and appropriate and safe traffic engineering techniques are applied to ensure that the mean operating speed of motorised traffic is kept to within 5 km/h of the speed limit.

 

2.5     60-km/h speed limit

A 60-km/h speed limit is an arterial route limit that may apply to roads in urban areas meeting specific design requirements. This speed limit may be appropriate where the roadside is fully developed, if the road geometry and other design features can safely provide for the activity generated by the development, when the traffic is operating at the higher speed.

A 60-km/h limit is only suitable on roads that primarily serve the needs of through traffic, (ie, a high proportion of the traffic should travel along the road for a significant proportion of its length). The road should have consistent geometric features over the whole length of the restriction to reinforce its route function.

Examples of the necessary design features include solid or flush medians, multiple lanes, frontage service roads, well-spaced intersections, restrictions placed on turns at minor intersections, property boundaries set back and linking of signals to discourage higher or lower speeds.

If a proposed 60-km/h speed limit will raise the existing speed limit, the road controlling authority should conduct a safety audit, as recommended in 3.6, to identify any deficiencies that require attention to provide a safe environment for all road users.

 

2.6     70-km/h speed limit

A speed limit of 70 km/h is appropriate in areas of intermediate roadside development, such as small country towns, urban fringe areas, short sections of road in partly built-up areas within a large urban traffic area or areas of single-sided development. It may also be used as a buffer between a 100-km/h and a 50-km/h section, but only if there is sufficient roadside development to make the speed limit reasonable and safe.

 

2.7     80-km/h speed limit

A speed limit of 80 km/h may be installed in the situations described below.

In all circumstances, an 80-km/h speed limit should not be posted over short lengths of road (see Table SLNZ1). The road should have consistent geometric features over the whole length of the speed restriction to reinforce its arterial route aspect.

 

2.8     Holiday speed limits

A holiday speed limit applies for a specified period or periods during a year. This may be suitable for locations with large differences in the level of roadside activity at different times of the year. An example is a beach resort that is popular in summer, but only sparsely populated for the rest of the year. Typically, when the level of activity is at its highest, a limit of 50 km/h would be appropriate, while for the remainder of the year the level of activity would justify the rural speed limit.

Because this type of speed limit is applied in unusual circumstances, the normal assessment methods are not fully appropriate. Appendix I sets out the method for determining a holiday speed limit.

 

3.0     Procedures for deciding on a speed limit

The posted speed limit must be safe and appropriate for the type and level of development on the adjacent land, and for the function and use of the road. When reviewing an existing speed limit or deciding the appropriate speed limit for a new road, the rule requires the speed limit to be calculated by following the procedures in SLNZ. This involves undertaking surveys and applying the procedures specified in this schedule to the survey data.

 

3.1     Surveys

Two surveys are required:

These surveys should be done together in accordance with the instructions in Section 4.0. Suitable survey forms are illustrated in Appendix II and in the computer program documentation.

For a 60-km/h speed limit, or if there is doubt about traffic complying with any other speed limit, a concealed survey of traffic speeds should be undertaken. Speed surveys should be carried out in accordance with LTSA guidelines on speed survey methods.

 

3.2     Road environment

Length of restriction

Frequent changes of speed limit along a route should be avoided. Minimum lengths of road for a speed limit must comply with clause 2.4 of the Setting of Speed Limits Rule. Table SLNZ1 complies with the rule, but specifies longer lengths in some situations as a guide to good practice. Applying these minimum road lengths will avoid having frequent changes in speed limit along a road with varying characteristics. However, these short lengths are not always appropriate, and longer lengths should be applied in some circumstances.

For example, consider a 500-metre section of road that has a calculated speed limit of 70 km/h, with a section of road at either end of it that has a calculated speed limit of 80 km/h. It may be appropriate to extend the 70-km/h section or one of the 80-km/h sections to reduce the number of changes in speed limit along the road. The decision as to which speed limit to extend, if either, will depend on factors such as the type of roadside development, the geometric standards, and the designation and use of the road.

The level of development should be reasonably consistent along the entire length of a speed limit, especially in areas with sparse development. It is not appropriate to install a 500-metre-long, 70-km/h speed restriction in a rural area, for example, if the only development is located in a 100-metre section of road in the middle of the proposed speed limit. This applies even if the requirement for the average rating is met for the 500-metre length. In these circumstances road users will see no reason for the change in speed limit and compliance will be poor. This will result in a wide variation in operating speeds, which makes judgement of speed and distance difficult for all road users. Such conditions will usually contribute to a reduction in safety, especially for pedestrians and cyclists.

 

Table SLNZ1 Minimum length of road for a speed limit

Speed limit
(km/h)
Nature of road and
adjacent speed limits
Minimum length
(metres)
50 Urban street, adjacent
speed limits 70 km/h or less

Urban fringe, adjacent
speed limits greater than
70 km/h
500


1000
60 Urban arterial route,
adjacent speed limits
80 km/h or less

Other situations
1000



500
70 Partly built up, adjacent
speed limits 80 km/h or less

Other situations
1000


500
80 Arterial route, adjacent
speed limits 70 km/h or less

Other situations
1000


800
100 All situations 2000

 

Changes in speed limit

Suitable points for changes in speed limit should be ascertained during the rating survey. All boundary points between speed limits must be at, or close to, a point of significant change in the roadside development or the road environment to emphasise the change in speed limit. Appropriate locations include a marked change in the level or type of roadside development, a change in the road geometry, a bridge, a threshold or other feature that affects speed (eg, a roundabout or a curve). As a guide, the first 200 metres either side of the change in speed limit should meet the appropriate rating for that speed limit. For example, if the proposed speed limit is 50 km/h to the north and 70 km/h to the south of the point where the speed limit changes, the first 200 metres to the north should rate 11 or more and the first 200 metres to the south should rate between 6 and 11.

A threshold treatment may be necessary to reinforce a change in the speed limit where there is no obvious change in the road environment.

When the difference between adjacent speed limits exceeds 30 km/h (for example, a change from 100 km/h to 50 km/h), special treatment may be necessary at the point of change to encourage road users to comply with the reduced speed limit. This may be achieved by installing a threshold or an oversize sign on each side of the road. Alternatively, a buffer zone can provide a transition area, but only when the rating and minimum length criteria are met for the speed limit used in the buffer zone. Whichever treatment is applied, it must be appropriate and encourage a safe response from road users in the transition zone.

Road geometry (60-km/h and 80-km/h arterial route limits)

60-km/h and 80-km/h speed limits are intended primarily for arterial routes.

The road geometry over the length of the route should be consistent, and to an appropriate standard. The geometric features to consider include lane widths, number of lanes, provision of a median, lighting, intersection controls, pedestrian and cycle facilities, signs and markings and the setback of the property boundary from the edge of the roadway. There should be no roadside development features that are inappropriate for the speed limit under consideration.

 

3.3     Signposting

Signposting must be correct to ensure a speed limit is enforceable and to encourage compliance. The rule requires every road controlling authority to provide, at or near, and no more than 20 metres from, the point on the road where the speed limit changes, a sign to advise drivers of the change in speed limit. The rule allows this small measure of flexibility when erecting the sign to avoid the sign being too close to a driveway, or to a point of restricted visibility. Changes in speed limit are frequently located at a specified distance from a side road. As most road reserves are 20 metres wide, the rule allows 20 metres flexibility in the location of the sign.

Where the operating speeds are high, or the change in speed limit is more than 30 km/h, additional or oversize signs may be appropriate. The Manual of Traffic Signs and Markings1 gives guidance on the sign size appropriate to the location and traffic conditions. Guidance is also given on the lateral placement and visibility requirements. Use of the manual is strongly recommended.

The rule requires repeater signs in all 60-, 70- and 80- km/h speed limit areas as shown in the following table:

Table SLNZ2     Maximum length of road between repeater signs

Speed limit (km/h) Maximum length of road
between signs (km)
60
2.0
70 2.4
80 2.6

 

1 Manual of Traffic Signs and Markings prepared and published by Transit New Zealand and the Land Transport Safety Authority. Part I: ISBN 0-478-04112-8, Part II: ISBN 0-478-04116-8.

 

The rule allows (but does not require) a road controlling authority to mark on the road surface alongside any speed limit sign the numerals shown on the sign.

 

3.4     Operating speeds

The mean speed and the 85th percentile speed on a road should not be significantly greater than the speeds specified in Table SLNZ3. On medium- to high-volume roads the standard deviation becomes important, as a road with a narrow distribution of speeds is less hazardous than one with a wide distribution. If operating speeds exceed the values specified in the table, it is likely that additional measures such as engineering, enforcement, education and publicity will be necessary to reduce speeds.

 

Table SLNZ3     Mean and 85th percentile operating speeds

Speed limit Mean speed
(km/h)
85th percentile speed
(km/h)
50 km/h
50 60
60 km/h 60 70
70 km/h 70 80
80 km/h 80 90
100 km/h 100 110

 

3.5     Crashes

Crash rate comparison

When proposing a speed limit for an arterial route, whether the proposal is an increase or reduction in speed limit, the overall injury crash rate for that section of road should be compared with national data. The overall crash rate includes intersection and mid-block crashes.

An examination of crash rates should be undertaken as a before-and-after study considering existing and future crash rates respectively.

The existing crash rate should be below the 85th percentile of the national crash rate for similar roads. If the crash rate exceeds the 85th percentile for similar roads, additional engineering and enforcement, in conjunction with the change in speed limit, will probably be required to reduce it. This is just as important when reducing the speed limit as when increasing it, because it is unlikely that a reduction in speed limit alone will reduce the crash rate.

To protect the safety of the road in the future, there should be no factors that will result in a worse crash rate after the speed limit is changed. The road should be monitored after the new speed limit is applied and any necessary remedial action taken to ensure the two-year average crash rate remains below the crash rate before the new limit was installed. If the crash rate exceeds the 85th percentile for similar roads with the new speed limit, engineering and enforcement action should be undertaken to reduce the crash rate below the 85th percentile.

The LTSA maintains a database of crash rates for arterial roads and some collector roads. This information is available for crash rate analysis. The comparison with similar roads should include as many of the characteristics listed below as possible, depending on the number of roads available with comparable characteristics. If necessary, the characteristics should be modified slightly to obtain a reasonable sample of similar roads, for example, combining roads with 50- and 60-km/h speed limits or roads serving different functions in the road network.

Road characteristics for comparison of similar roads:

The crash rate comparison is important for proposed speed limits on arterial routes and is recommended practice for all speed limit proposals.

Special crash-type analysis

On arterial routes, when a change in speed limit is proposed, crashes should be analysed to identify crash-types that may be affected by a different speed limit. Data should be analysed for the last two years with particular attention paid to pedestrian, cycle, turning and crossing crashes as the types most likely to be affected by a change in speed limit. Special crash-types should be monitored after the new speed limit is installed, and any necessary remedial action taken to ensure the two-year average crash rate does not increase for any of the identified crash-types.

Special crash-type analysis is important for proposed speed limits on arterial routes and is recommended practice for all speed limit proposals.

 

3.6     Safety audit

Road controlling authorities are responsible for providing a safe environment for all road users on their roads. This is reflected in clause 2.5 of the Setting of Speed Limits Rule, which requires road controlling authorities to ensure all traffic control devices are safe, effective and appropriate to a new speed limit before it is applied. To ensure this condition of the rule is complied with, a safety audit, appropriate to the location and function of the road, should be conducted. This is particularly important when it is proposed to raise the existing speed limit. Suitable procedures and checklists are provided in Transit New Zealand’s Safety Audit Policy and Procedures2 or the Austroads Road Safety Audit3 guidelines.

2 Safety Audit Policy and Procedures, August 1993. Published by Transit New Zealand as a guideline document. ISBN 0-478-04113-6.

3 Road Safety Audit, 2nd Edition 2002. Published by Austroads as a joint Standards Australia and Standards New Zealand handbook, HB43:2001. ISBN 0 85588 589 0.

 

3.7     Documentation

Good documentation of the speed limit setting procedures must be kept. This allows the speed limit setting process to be audited. It also allows the traffic enforcement agency to provide the courts with full documentation to support a prosecution if this is necessary. Good documentation provides an historical record of the speed limit, which will simplify future reviews of it.

The following information should be retained for all speed limits:

The rule requires a register recording all speed limits, other than temporary speed limits, to be kept for the roads under a road controlling authority’s control. The register must be available for public inspection. For details, refer to the LTSA guidelines on keeping a speed limits register.

 

3.8     Monitoring and review

Regular reviews of speed limits should be carried out to ensure they keep pace with changes in the level of development on adjacent land, the use of the road or road geometry. This will ensure a consistent standard is maintained throughout the country. The location, condition and visibility of the signs should also be monitored.

Monitoring should cover six main areas:

 

4.0     The decision-making process – calculating the speed limit

A rating diagram must be prepared for each section of road under consideration. A general information form must be completed for all arterial and major collector roads and should also be completed for a minor collector or local road if it is the only road being reviewed or if there are matters requiring special consideration for setting the speed limit. The survey forms in Appendix II are designed for this purpose. A4-size survey form templates in Microsoft Word format are available from the LTSA.

The following information should be recorded on the survey forms:

The survey should extend at least 200 metres in each direction beyond the section of road under consideration. This is to ensure the appropriate boundary point between speed limits is identified and features that may influence sign location are included.

The survey data is used to calculate the average rating, which is then used as an input to a flow chart to determine the appropriate speed limit for the section of road. The average rating has two components, the development rating and the roadway rating. These are described in the following sections.

 

4.1     Development rating

Different types of development are allocated the rating values as shown in Table SLNZ4. The ratings are based on the expected number of vehicle, pedestrian and cycle movements generated each day. For example, a house is allocated one rating unit and a large shop is given four rating units.

Development ratings are allocated for the road being surveyed (frontage development) and for the first 500 metres of side roads (side road development). For each 100-metre section of road, the development rating sub-total is the sum of the frontage and the side road development ratings. The total development rating is calculated by adding the 100-metre sub-totals for the length of road being assessed for a speed limit.

 

Frontage development

Table SLNZ4 Frontage development rating units

Development type Frontage development Rating units
A Property or access point (Note 1) with 1 or 2 dwellings (Note 2); church; small hall; playground; beach; sports ground; camping ground; holiday cabins; cycle path or pedestrian way that intersects with the roadway 1
B Property or access point (Note 1) with 3 or 4 dwellings (Note 2); business or office with fewer than ten employees; small shop; large hall; cinema; small public swimming pool 2
C Property or access point (Note 1) with 5 or more dwellings (Note 2); business or office with 10 to 30 employees; general store; takeaway shop; bank; service station; cinema complex; hotel; restaurant; large swimming pool 3
D Business or office with more than 30 employees; large shop; post office; hospital; tertiary education establishment 4
E Access point (Note 1) serving two or more developments 1 to 4 (Note 3)
F Primary school or kindergarten 1 for every 15 pupils
G Secondary school 1 for every 30 pupils

Note 1. An access point includes a private driveway and a public entrance or exit.

Note 2. A dwelling includes a house, a home unit in a block, a semi-detached home unit and a motel unit. Each unit in a block of units counts as one dwelling.

Note 3. When two or more developments other than dwellings, or if dwellings and other developments share a common access point or service road, the correct rating is the greatest of:

 

Multiple access points

In most situations where a single development or a small group of developments has more than one access point on the same road, the development should be rated once only and additional access points ignored. Developments with separate entrance and exit points should also be treated as having only one access point. Examples include service stations, motels, schools and a small group of shops with off-street parking.

However, where a large group of developments, such as a shopping mall or a service road, share more than one access point, it is appropriate to assign a rating to each of them. In these situations a proportional number of the developments should be allocated to each access point, and each one rated as a development type E as described in Table SLNZ4.

Separate ratings may be assigned to each access point when there are at least four individual developments or one type D development (as described in Table SLNZ4) for each access point. These conditions ensure that the sum of the access point ratings does not exceed the sum of the ratings for the individual developments in the group.

Side road development

The side road development rating is calculated by applying the rating values specified in Table SLNZ4 to the development on the first 500 metres of a side road and then using Table SLNZ5 to determine the side road rating. Please note that a school or kindergarten on a side road is rated differently from normal. For each school or kindergarten fronting the first 500 metres of a side road, use half the normal frontage rating (from Table SLNZ4) to determine the side road rating from Table SLNZ5. If a school or kindergarten is between 500 and 1000 metres from the road being surveyed, use a quarter of the normal frontage development rating.

For example, a side road with seven driveways to single houses and a primary school with 240 pupils within the first 500 metres has a frontage development rating (R) of 7+ (16÷2) = 15. By using the value R=15 in Table SLNZ5, the side road development rating is ‘2’, if traffic flow on the side road is less than 4000 vehicles a day and ‘3’, if traffic flow on the side road is 4000 vehicles a day or more.

Note that a cross intersection is treated as two side roads.

Table SLNZ5     Side road development rating units


Traffic flow
on side road
(V = vehicles
per day)
Side road development rating units
according to the frontage development rating
(R) on the first 500 m of the side road
R < 8 8 ≤ R < 20 R ≥ 20
V < 4000 1 2 3
V ≥ 4000 2 3 4

 

4.2     Roadway rating

The roadway rating is calculated by adding together the ratings relating to a number of roadway activities – pedestrians, cyclists, parking, geometry, traffic control and use of the road. Different ratings apply, depending on the frequency of activities, the closeness of the activity to through traffic etc. Tables SLNZ6 to SLNZ11 show the ratings that apply according to the nature and use of the road. Note that where usage or provision of facilities is different on each side of the road, the rating is the average of the ratings for each side.

Roadway ratings are allocated for each 100-metre section of road and the sub-total is the sum of the ratings for each roadway activity per 100-metre section. The total roadway rating is calculated by adding the 100-metre sub-totals for the length of road being assessed for a speed limit.

The total roadway rating for the length of road under consideration must not exceed the total development rating. (See 4.3 Average rating for what to do if the roadway rating exceeds the development rating.)

 

Table SLNZ6     Roadway rating – pedestrians

Pedestrian facilities Pedestrian
volume less
than 200 per
day
Pedestrian
volume 200 per
day or more
Footpaths behind grass berms or no
pedestrian access
0 0
Footpaths adjacent to roadway 0 1
No footpath but useable shoulder 1 2
Pedestrians must walk on roadway 1 3

 

Table SLNZ7     Roadway rating – cyclists

Cycle facilities Cycle volume
less than 200
per day
Cycle volume
200 per day or
more
Cycleway behind berms or fence or no
cycle access
0 0
Wide road, cycles clear of moving traffic 0 1
Narrow road, cycles impede moving traffic 1 2

 

Table SLNZ8     Roadway rating – parking

Parking facilities Normally
two parked
vehicles or
fewer per
100 metres
Frequent
parking on
both sides,
long
duration
Frequent
parking on
both sides,
short
duration
Vehicles can park 2 metres from
moving traffic
0 0 1
Vehicles park close to moving
traffic but do not obstruct it
1 2 3
Parked vehicles obstruct moving
traffic, ie, remaining traffic lane 3
metres or less
2 3 4

 

Table SLNZ9     Roadway rating – geometry

Type of roadway Alignment
Open
visibility
Average
visibility
Limited
visibility
Divided carriageway (solid median
or barrier) or one way
0 0 0
4 or more lanes (flush median or
undivided)
0 1 1
2 or 3 lanes (flush median or
undivided)
0 1 2
1 lane (two way) 3 4 5

 

Table SLNZ10     Roadway rating – traffic control

Traffic control
(Applying to traffic on the road surveyed)
Rating units
Pedestrian crossing 3
‘Stop’ control 3
‘Give Way’ control 2
Traffic signals 2
Railway level crossing 1
Traffic islands 1

 

Table SLNZ11     Roadway rating – use

Type of development Status of road
Local road Collector road Arterial road
Residential 2 1 0
Industrial 1 0 0
Commercial 0 0 0
Rural residential 1 0 0
Rural 0 0 0

 

4.3     Average rating

The average rating is calculated by adding together the total development and roadway rating for the length of road being assessed and then dividing by the number of 100-metre sections of road. However, the total roadway rating must not exceed the total development rating for the length of road being assessed. If the total roadway rating is higher, it must be reduced to that of the development rating.

When using the computer program, enter the number of each type of development and roadway feature onto the screen. The program applies the appropriate rating units and adds and divides the figures to calculate the average rating. If necessary, the program automatically reduces the roadway rating to that of the development rating so the total rating never exceeds twice the development rating. If you choose not to use the computer program, you must apply the correct rating figures according to Tables SLNZ4 to SLNZ11 and calculate the average rating value manually.

When the average rating has been determined, the speed limit flow charts shown in Figures SLNZ1 to SLNZ4 can be used to determine the calculated speed limit.

 

4.4     Speed limit flow charts

Figure SLNZ1 shows different surrounding land environments and how they relate to the flow charts for the rural, in-between or urban locations. The process of determining the appropriate speed limit according to the character of the road and the average rating is detailed in Figures SLNZ2, 3 and 4. Choose the appropriate flow chart and follow it through to select the speed limit.

For a limited access arterial road, such as a motorway or expressway, in either an urban or rural location use the in-between flow chart shown in Figure SLNZ3.

 

Table SLNZ12     Speed limit flow chart summary table

Average rating (R) Speed limit (km/h)
Rural location In-between
location
Urban location
R ≥ 11 Note 1 50 50
R ≥ 11 with
engineering to
control mean speed
within 5 km/h of the
limit
Note 1 Note 2 20, 30 or 40
R ≥ 11 with specific
urban arterial
features
Note 1 60 60
11 > R ≥ 6 70 70 70
6 > R ≥ 3 80 80 80
R < 3 100 100 Note 1

Note 1. The average rating and level of development is not consistent with the location of this road. Please refer to Figure SLNZ1 and select the appropriate location according to the surrounding land environment.

Note 2. 20-, 30- or 40-km/h speed limits should only be installed on local roads or minor collector roads in urban traffic areas.

 

Figure SLNZ1 Rural/In-between/Urban

Rural/in-between/urban

 

Figure SLNZ2 Speed Limit Flow Chart – Rural

Speed limit flow chart - rural

 

Figure SLNZ3 Speed Limit Flow Chart – In-Between

Speed limit flow chart - in-between

 

Figure SLNZ4 Speed Limit Flow Chart – Urban

Speed limit flow chart - urban

 

Glossary

Arterial road
An arterial road is one that primarily serves the function of carrying through traffic. It is a major road in the roading hierarchy for the area and carries the highest volume of traffic. (See also collector road and local road.)
Collector road
A collector road serves the function of collecting and distributing traffic in the network. It interfaces between arterial and local roads and carries moderate traffic volumes compared to the other classes of road. (See also arterial road and local road.)
Fully protected median
A fully protected median is one that is wide enough to provide a safe area, clear of straight through traffic, for vehicles waiting to turn or cross the median. This usually requires a median width of at least 4.5 metres at the points where traffic turns or crosses.
Local road
A local road serves the primary function of providing access to property. It is the lowest classification in the network and carries less traffic than the other classes of road in the area. (See also arterial road and collector road.)
Setback
The setback is the distance from the property boundary to the nearest edge of a through traffic lane.
85th percentile
(85th %ile)
The 85th percentile is the value at which 85% of the sample is included. Only 15% of the sample will exceed the 85th percentile. In speed sample analysis, 85% of the vehicles surveyed will travel at or below the 85th percentile speed. For crash rate comparisons, 85% of roads included in the sample of similar roads will have a crash rate equal to or less than the 85th percentile crash rate.

 

Appendix I

Holiday speed limits

1.     Background

At some locations, traffic conditions require road users, in the interests of safety, to moderate their speed more during holiday periods than at other times. This creates a case for lower speed limits during the holiday periods to assist road users in their choice of speed.

 

2.     Period of application

To maintain a reasonable level of national uniformity, the period during which the lower speed restriction applies will normally be as described below.

It is sometimes reasonable to depart from the dates mentioned above if, for example, the location is a popular winter holiday resort or to obtain a reasonably uniform period of application throughout a particular region.

If the holiday speed limit applies to an arterial road, the effect on through traffic must be considered and the period of application should be kept to a minimum.

 

3.     Holiday speed limit

The road must be surveyed during the period the holiday limit will apply. Each bach, house or other dwelling (including a tent or caravan) is rated as one unit. A higher than normal roadway rating is acceptable, but must not exceed two thirds of the total rating. The operating speed of the traffic should be measured during the period of the proposed holiday speed limit and comply with section 3.4 of this schedule. Table SLNZ13 shows the necessary rating for a 50-, 70- or 80-km/h holiday speed limit.

 

Table SLNZ13     Average rating for holiday speed limits

Average rating (R) Speed limit
R ≥ 9 50 km/h
9 > R ≥ 6 70 km/h
6 > R ≥ 3 80 km/h

A 20-, 30-, 40- or 60-km/h speed limit will not usually be appropriate for a holiday speed limit due to the special engineering features required. However, if a 20-, 30-, 40- or 60-km/h speed limit is being considered for a holiday speed limit, it must comply with the requirements set out in the rule and the standard procedures in sections 1-4 of this schedule, except for the rating. The normal rating for a 20-, 30-, 40- and 60-km/h speed limit is the same as for a 50-km/h limit, so an average rating of 9 or more is acceptable, as shown for a 50-km/h holiday speed limit in Table SLNZ13.

The normal off-season speed limit should be calculated using the standard rating criteria, counting permanently occupied residences only (ie, exclude holiday dwellings and camp sites that are not occupied all year round).

Information that should be documented for a holiday speed limit includes:

 

4.     Signposting and notification

It is essential that the signs are changed at the beginning and end of the holiday periods. It is also recommended that the changes in speed limits are publicised.

 

Appendix II

Survey forms

Speed limit survey form (rating diagram)

 

General information form - page 1

General information form - page 2

 

Example of Completed Rating Diagram

Speed limit survey form (rating diagram) - sample showing completed form

Land Transport Rule - Setting of Speed Limits - Rule 54001
Land Transport Safety Authority of New Zealand, Te Mana Marutau Waka Whenua o Aotearoa