Assessment of Road Improvements

Archive - this information is for reference only and no longer maintained.

Introduction

This section provides guidance for assessing road improvement activities over $300,000 implementation cost per activity that target a specific increase in levels of service in part of a roading network.

 The road improvements activity classes include Local Road Improvements, State Highway Improvements and Regional Improvements, under the following work categories:

• Work category 321 – New traffic management facilities
• Work category 322 – Replacement of bridges and structures
• Work category 323 – New roads
• Work category 324 – Road improvements
• Work category 325 – Seal extension
• Work category 331 – Property purchase – state highways
• Work category 332 – Property purchase – local roads
• Work category 333 – Advance property purchase - local roads
• Work category 341 – Minor improvements
• Work category 357 – Resilience improvements

Strategic fit for road improvements

Default strategic fit

By default, the strategic fit rating for road improvements is low.

Requirements for medium rating

A medium strategic fit rating may be given if the problem, issue or opportunity involves:

• journeys for:
  • employment,
  • access to economic opportunities,
  • access to social opportunities,
  • tourism, and/or
  • freight;

where a demonstrated gap in the customer levels of service has been identified for: 

• • journey time reliability,
  • resilience (including lifelines),
  • mismatched capacity and demand that results in congestion, and/or
  • mismatched capacity and demand that results in capacity constraints

AND/OR

• a medium crash risk

Requirements for high rating

A road improvement activity must only be given a high strategic fit rating if the problem, issue or opportunity involves:

• Journeys for: 
  • employment,
  • access to economic opportunities,
  • tourism, and/or
  • freight;

and has a significant gap in the customer levels of service for: 

• • journey time reliability,
  • resilience (including lifelines),
  • mismatched capacity and demand that results in severe congestion, and/or
  • mismatched capacity and demand that results in capacity constraints

AND/OR

• a high crash risk

Further information

Further information on Strategic Fit assessment is provided in the guidance on Developing an Assessment Profile. Definitions of high and medium crash risk are provided below.

 High crash risk definition

The intersection, corridor or route is assessed to be high or medium to high collective risk according to one or more of the following definitions in:

• The High-Risk Intersections Guide; or
• The High-Risk Rural Roads Guide; or
• Urban KiwiRAP (external link)corridor risk mapping protocols; or
• Safer Journeys for Motorcycling on New Zealand Roads.(external link)

Notes:

1. 1. The acceptable methods of determining high-risk from the High-Risk Intersections Guide are:
      1. Where 3 or more fatal and serious crashes have been reported at an intersection in a 5 year period, or 5 or more in a 10 year period; or
      2. Where the estimated DSI (deaths and serious injuries) casualty equivalents (Collective Risk) at an intersection is ≥1.1 (based on a 5 year period) i.e. High or Medium-High Collective Risk.
   2. The acceptable methods of determining high-risk from the High-Risk Rural Roads Guide are:
      1.  Where the number of fatal and serious crashes along a route results in a High or Medium-High Collective Risk, as calculated from Figure 4-1 in the guide and based on a 5 year period; or
      2. Where the number of fatal and serious crashes per 100 million vehicle kilometres travelled along a route results in a High Personal Risk, as calculated from Figure 4-2 and based on a 5 year period; or C. The route has a Star Rating of less than or equal to 2.
   3. The acceptable methods of determining high-risk from Urban KiwiRAP(external link) are:
      1. Where the estimated DSI casualty equivalents along a corridor results in a High or Medium-High Collective Risk, based on a 5 year period; or
      2. Where the estimated DSI casualty equivalents per 100 million kilometres travelled along a corridor is greater than 20 (based on a 5 year period) and there have been 3 or more injury crashes in the past 5 years.
   4. The acceptable method of determining high-risk from Safer Journeys for Motorcycling on New Zealand Roads is where the number of motorcycle injury crashes along the route per year per km results in a High or Medium-High Collective Risk, as calculated from Figure 4-1 in the guide and has 2 or more motorcycle injury crashes in a 5 year period or 4 or more in a 10 year period.

 Medium crash risk definition

The intersection, corridor or route is assessed to be medium collective or medium-high personal risk according to one or more of the following definitions in:

• The High-Risk Intersections Guide; or
• The High-Risk Rural Roads Guide; or
• Urban KiwiRAP(external link) corridor risk mapping protocols; or
• Safer Journeys for Motorcycling on New Zealand Roads(external link).

Notes:

1. 1. The acceptable methods of determining medium-risk from the High-Risk Intersections Guide are:
      1. Where the estimated DSI casualty equivalents (Collective Risk) at an intersection is greater than or equal to 0.6 (based on a 5 year period) i.e. Medium Collective Risk; or
      2. Where the estimated DSI casualty equivalents per 100 million vehicle kilometres travelled (Personal Risk) at an intersection is greater than or equal to 16 (based on a 5 year period), i.e. Medium-High Personal Risk.
   2. The acceptable methods of determining medium-risk from High-Risk Rural Roads Guide are:
      1. Where the number of fatal and serious crashes along a route results in a Medium Collective Risk, based on a 5 year period; or
      2. Where the number of fatal and serious crashes per 100 million vehicle kilometres travelled along a route results in a Medium-High Personal Risk, as calculated from Figure 4-2 in the guide and based on a 5 year period.
   3. The acceptable method of determining medium-risk from the Urban KiwiRAP(external link) are:
      1. Where the estimated DSI casualty equivalents along a corridor results in a Medium Collective Risk, based on a 5 year period; or
      2. Where the estimated DSI casualty equivalents per 100 million kilometres travelled along a corridor is greater than 12 (based on a 5 year period) and there have been 2 or more injury crashes in the past 5 years.
   4. The acceptable method of determining medium -risk from Safer Journeys for Motorcycling on New Zealand Roads is where the number of motorcycle injury crashes along the route per year per km results in a Medium Collective Risk, as calculated from Figure 4-1 in the guide.

Effectiveness for road improvements

Criteria for effectiveness

All six criteria set out below are to be assessed for any programme or activity proposed for NLTP inclusion or funding approval. The explanations are a guide to assessment, highlighting aspects that need to be considered. If any of these aspects is not applicable to the activity then it should not form part of the assessment.

Further information

Further information on Effectiveness assessment is provided in the section on Developing an Assessment Profile.

Benefit and cost appraisal for road improvements

Requirements

The required benefit and cost appraisal methodology for road improvements is benefit-cost analysis and the required measure is the benefit-cost ratio (BCR).

The Transport Agency requires that Approved Organisations and the Transport Agency (state highways) use the Transport Agency Economic Evaluation Manual(external link) procedures and templates to determine the BCR for road improvement activities.

Ratings

If the calculated BCR is below 1.0, then the activity is considered to be economically inefficient. In this case, no rating for benefit and cost appraisal will be given.

Assuming that the BCR is 1.0 or higher, the benefit and cost appraisal for road improvements falls into one of three bands:

BCR range 1- 3

All activities with BCR greater than or equal to 1 and below 3 are prioritised in this band.

BCR range 3 - 5

All activities with BCR greater than or equal to 3 and below 5 are prioritised in this band.

BCR range > 5

All activities with BCR greater than or equal to 5 are prioritised in this band.

Non-monetised benefits and additional benefits

Non-monetised benefits may be taken into account and, if the Transport Agency considers these benefits to be significant, may result in a higher rating.

Additional benefits are usually in the form of wider economic benefits that are not specifically covered by the Transport Agency’s Economic Evaluation Manual. Additional benefits may result in a higher rating or be presented as part of sensitivity analysis.

Use of generic or default BCR

In specific cases generic or default BCRs may be used in lieu of a calculated BCR for the activity. These are:

• Stock Effluent Facilities - a generic BCR of 12 may be applied to a stock effluent facility, as identified in the National Stock Effluent Strategy, instead of a calculated BCR
• Projects which are evaluated on a whole of life, net cost present value basis, e.g. bridge renewals. A default BCR of 99 will be applied to an activity instead of a calculated BCR. The present value evidence must be attached in TIO to support the 99 rating. Where an improvement component exists in such a project, it must be supported by a calculated BCR.

No other placeholder, generic or default BCRs are to be used.

Peer review

The Transport Agency reserves the right to require a peer review of benefit and cost appraisal determinations and measures, including any non-monetised/additional benefits and adverse impacts, regardless of the scope, prior to an investment decision.

Insufficient information (1*)

An activity can be included in the National Land Transport Programme (NLTP) when no benefit and cost appraisal has been made or when no robust evidence is lacking to support the assessment. In such cases the rating for benefit and cost appraisal will default to 1 for improvement activities. The Transport Agency represents these activities as 1* to indicate that more information is required to achieve a robust assessment profile.

An activity will not be considered for funding approval with a 1* status.

Further information

Further information on Benefit and Cost Appraisal is provided in the section on Developing an Assessment Profile.