Assessment of local road, regional and state highway improvement activities

Prior requirements for assessment

Before an investment proposal is assessed against the Investment Assessment Framework (IAF), a business case must be developed, which Waka Kotahi NZ Transport Agency assesses to ensure it:

is robust and has been developed using business case approach (BCA) principles
meets the requirements for being included in the National Land Transport Programme (NLTP) and is eligible for NLTP funding.

The activity must be included in a regional land transport plan (RLTP).

For further information about prior requirements, see Developing an assessment profile.

Work categories

Work categories
The road improvements activity classes include local road improvements, state highway improvements and regional improvements, under the following work categories:
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Results alignment

For road improvement activities, the results alignment can be low, medium, high or very high (see below).

For further information on results alignment assessment see Developing an assessment profile which includes definitions of terms used. Definitions of high and medium crash risk are provided below.

Requirements for a low rating

A road improvement activity may be given a low results alignment rating if the activity addresses one or more of the following criteria:

Strategic priority	Criteria for a low rating
Safety	Addresses safety gaps with reference to the One Network Road Classification (ONRC)
Access – thriving regions, liveable cities	Addresses identified resilience gap or impediments to accessing social and economic opportunities

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Requirements for a medium rating

A road improvement activity may be given a medium results alignment rating if the activity addresses one or more of the following criteria:

Strategic priority	Criteria for a medium rating
Safety	Addresses safety issues presenting a medium crash risk, affecting communities subject to medium safety risk, and/or in Safer Journeys area of medium concern
Access – thriving regions	Addresses an identified gap in an approved regional economic development (RED) programme Addresses a significant resilience gap or impediment to access on regionally important social and economic connections Supports priority elements in agreed integrated land use and multi-modal plans in regions Makes best use of key corridors that prioritise regional freight and tourism Provides operational efficiencies to reduce the costs of meeting appropriate levels of service without impacting benefits adversely
Access – liveable cities	Addresses significant gap in access to social or economic opportunities Address identified gap in access to new housing in medium-growth urban areas Addresses identified resilience risk to continued operation of the network Addresses significant gap in integrated intermodal and user information, and significant deficiencies in network operation Provides operational efficiencies to reduce the costs of meeting appropriate levels of service without impacting adversely on benefits
Environment	Enables reductions in environmental and public health harms, particularly arising from land transport-related air pollution, noise, and impact of construction and ongoing use of transport infrastructure on water quality and biodiversity Addresses long term reductions in greenhouse gas emissions from land transport

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Requirements for a high rating

A road improvement activity may be given a high results alignment rating if the activity addresses one or more of the following criteria:

Strategic priority	Criteria for a high rating
Safety	Addresses safety issues presenting a high crash risk, affecting communities subject to high safety risk, and/or in Safer Journeys area of high concern Addresses safety issues presenting a high societal consequence risk
Access – thriving regions	Enables a significant regional economic development opportunity in an approved RED programme Addresses significant resilience gap or impediment to access on nationally important social and economic connections Addresses a gap in an approved RED programme in high priority RED regions Makes best use of key corridors that prioritise national freight and tourism Provides significant operational efficiencies to reduce the costs of meeting appropriate levels of service without impacting adversely on benefits
Access – liveable cities	Supports high priority elements in agreed integrated land use and multi-modal plans address significant gap in access to new housing in high-growth urban areas Addresses a significant resilience risk to continued operation of the network Makes best use of key corridors that prioritise multi-modal use and freight Provides significant operational efficiencies to reduce the costs of meeting appropriate levels of service without impacting benefits adversely
Environment	Addresses significant reductions in environmental and public health harms, particularly arising from land transport-related air pollution, noise, and impact of construction and ongoing use of transport infrastructure on water quality and biodiversity Addresses long term significant reductions in greenhouse gas emissions from land transport.

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Requirements for a very high rating

A road improvement activity will only be given a very high results alignment rating if the activity addresses one or more of the following criteria:

Strategic priority	Criteria for a very high rating
Safety	Implements a speed management approach focusing on treating the 10 percent of the network that will result in the greatest reduction in deaths and serious injuries (DSI) Targets areas of high collective risk with high DSI reduction measures that achieve a DSI reduction of at least 40% .

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Cost–benefit appraisal

Waka Kotahi requires approved arganisations and Waka Kotahi (state highways) to use the Waka Kotahi Monetised benefits and costs manual (from August 2020) or Economic evaluation manual (superseded August 2020) procedures and templates to determine the benefit–cost ratio (BCR) for road improvement activities.

Non-monetised benefits and additional benefits should also be considered where appropriate.

For further information on cost–benefit appraisal including calculating the BCR and resulting rating see Developing an assessment profile.

Safety risk definitions for results alignment

Risks change over time, and up-to-date trends should be monitored to ensure safety programmes are addressing the biggest risks.

See Safety risk definitions for results alignment for details.

Resilience thresholds for results alignment

Waka Kotahi has set threshold levels for investment activities to address resilience. These take into account the expected duration and frequency of the road closure, the road's classification and any alternative routes. These thresholds can be used to determine when it is appropriate to propose investment activities to overcome resilience problems.

Route closures and results alignment
Results alignment is based on the number of route closures.
The table of acceptable closures provides the annual rate [note 1 below] for each road class when there is a viable alternative route. If there is no viable alternative route [note 2 below] the acceptable number of closures in the table is decreased by a factor of 2.5 (ie for a regional or arterial road the number of acceptable closures becomes 4 instead of 10 closures per year for the two to four hour closure period).
The resilience gap for results alignment is:
o    low if all values of the number of road closures are lower than the values shown in the table (adjusted for whether a viable alternative route exists)
o    medium if one or two values are greater than or equal to the values shown in the table (adjusted for whether a viable alternative route exists)
o    high if three or more values are greater than or equal to the values shown in the table (adjusted for whether a viable alternative route exists).
Notes:
1. Average values are taken over at least a five-year period
2. A viable alternative route is defined as:
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Table of acceptable closures

The table below shows the acceptable number of road closures per year for ONRC road classes when there is an alternative route.

Closure period	ONRC classification
Closure period	National high volume	National	Regional/ arterial	Primary/secondary collector	Access/access low volume
2–4 hrs	1	4	10	19	30
5–12 hrs	0.5	2	5	9.5	14.8
13 hrs–2 days	0.2	1	2	3.8	5.9
3–5 days	0.1	0.2	0.5	0.9	1.5
6–14 days	0.04	0.08	0.2	0.4	0.6
15–49 days	0.02	0.04	0.10	0.19	0.30
50–120 days	0.01	0.01	0.025	0.047	0.074
More than 120 days	0.004	0.004	0.010	0.019	0.030

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Mitigation of road-traffic noise

Structural mitigation can be considered when road-traffic noise levels, as predicted by strategic mapping undertaken in accordance with the Guide to state highway noise mapping [PDF, 615 KB] (Draft) November 2013, exceed 65dB L_Aeq(24hr) at protected premises and facilities (PPF).

The criteria for road-traffic noise mitigation are:

the number of PPF exposed to road-traffic noise above 65 dB L_Aeq(24hr)
the number of PPF that would benefit from the mitigation.

Definition of PPF

PPF is defined in NZS6806:2010(external link). PPFs in urban areas should be located at a distance of less than 100m from the edge of the road seal. PPFs in rural areas should be located at a distance of less than 200m from the edge of the road seal.

Road particulates

The assessment methodology for road particulates provides a risk rating of low, medium or high.

To determine the risk rating, use the following tables:

Table 1: Use this to assess whether there is a need to mitigate road dust for a particular section of road. The dust risk score is calculated by totalling the scores for each of the 11 individual factors.
Table 2 : Use this to calculate the site dust risk score which will fall into one of three dust risk categories. Table 2 provides a first order assessment of the potential benefits gained by mitigating a section of unsealed road and indicates what action (if any) is needed to complete the decision-making process.

Table 1: Site dust risk factors and scores

Risk factor/score	0	1	2	3	4	5
Traffic
5-day annual average daily traffic (AADT) of HCVs*	0	1–5	6–10	11–25	26–50	More than 50
Speed limit of HCVs* (km/h)	No HCVs	20km/h	50km/h or greater
5-day AADT of LCVs**	Less than 100	101–300	More than 300
Speed of LCVs** (km/h)	Less than 50	50–70	Greater than 70
Receptors (within 80m of roadway)
Number of dwellings (houses/km)	0	1	2–4	5–7	8–10	More than 10
Other locations where people are likely to be exposed (eg schools, marae, or hospitals) (sensitive locations/km)	None	1–2	3 or more
Ecologically sensitive areas such as rare species habitats or wetlands (sensitive locations/km)	None	1–2	3 or more
Horticultural sensitive areas such as fruit orchards (sensitive locations/km)	None	1–2	3 or more
Site characteristics
Location of roadway	Open plains or costal area	Some land features likely to slow winds	Inland enclosed valley
Frequency of rain days (> 5mm)	More than 2 events per week	0–1 event per week	Less than one event every 2 weeks
Longevity of logging route use	Not a logging route	1–2 years	Longer than 3 years

Notes:

*HCV = heavy commercial vehicle (vehicle with gross vehicle mass greater than 3,500kg). Research report 590 uses HDV which has been amended to HCV to reflect sector terminology.

**LCV = light commercial vehicle (vehicle with a gross vehicle mass of less than 3,500kg). Research report 590 uses LDV which has been amended to LCV to reflect sector terminology.

Calculations use a five-day average of the AADT from Monday to Friday

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Table 2: Risk category and actions

Total dust risk score	Dust risk category	Potential benefit from dust mitigation	Action to be taken
0–9	Low risk	Little or no benefit from mitigation	End of decision-making process
10–19	Medium risk	There may some benefit from mitigation	Return to and repeat the ‘Site dust risk factors and scores’ with refined site-specific information
20–38	High risk	There is likely to be a benefit from mitigation	Complete assessment of suitable mitigation options

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Reference for dust risk assessment

Waka Kotahi research report 590, Impacts of exposure to dust from unsealed roads, provides a methodology to assess the level of health risk associated with individual unsealed roads. Undertaking an assessment using this methodology produces a numerical output which can then be used to determine the relative level of risk of harm to human health from unsealed roads. Approved organisations can also reference the National Environmental Standards (NES) for particulates which cover road dust, vehicle emission particulates, tyre dust, etc.
Research report 590 uses HDV and LDV which have been amended to HCV and LCV to reflect sector terminology.
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Online services

Assessment of local road, regional and state highway improvement activities

Archive - this information is for reference only and no longer maintained.

Introduction

Prior requirements for assessment

Work categories

Results alignment

Cost–benefit appraisal

Safety risk definitions for results alignment

Resilience thresholds for results alignment

Mitigation of road-traffic noise

Road particulates