Safety works investment prioritisation process (SWIPP)

SWIPP is the national database that combines a list of high-risk sites/routes and areas for potential projects. The Safety Projects Programme comprises a schedule of identified future works that can be separately classified as Minor Improvement or Safety Improvement projects. The NOC Contractor is required to provide support to the Principal to develop this programme. The current format used by the Principal is Safety Works Investment Prioritisation Process (SWIPP) spread sheets.

SWIPP manual [PDF, 2.9 MB]

To login to SWIPP, follow this link:
https://swipp.nzta.govt.nz/login(external link)

For further information contact:
AskPAT@nzta.govt.nz

Transport Services – System Management Contacts

Our System Management Team is accountable for delivery of our Network Outcome Contracts and investment with our local government partners.

Communication is key for the success of our business. Use the tool below to select a location and see the local and national leads for each function area.

Note, this list will be updated accordingly throughout the year.

Performance aggregate tool

The T10 specification outlines the process for implementing the state highway skid resistance policy as part of Waka Kotahi NZ Transport Agency safety management for the state highway network. The objective of this specification is to provide a nationally consistent and proactive approach to the management of skid resistance on the state highway network.

T10 Specification for state highway skid resistance management [PDF, 292 KB]

Section 12 of the specification sets out the detail in selecting surfacing aggregate such that new surfacing design shall include an estimation of expected life. The fundamental requirement for new surfacing aggregate selection is:

  • Aggregates should be selected with the objective of maintaining the skid resistance at or above the IL for the design life of the surfacing. Where this is not cost effective, alternative aggregates may be used.

Surfacing aggregate may be selected by one of two methods:

  • Aggregate performance method
  • Polished stone value (PSV) method

The preferred method for aggregate selection is the aggregate performance method. However, if sufficient information is not available, the PSV method may be approved for use.

The aggregate performance method entails using data on the polishing of aggregate (ESC achieved over the life of the surfacing).

The performance aggregate tool takes the annual HSD survey data and creates a matrix of aggregate performance in a variety of polishing stress situations normalised for heavy traffic and covers aggregates across the country and should be referred to when agreeing treatments and expected performance.

It also draws the data from RAMM and shows the performance of sealing aggregate over time. 

Performance aggregate tool(external link) (Stantec website)

How to use

Select a point in any graph (or combinations of points) and it creates a filter based on that selection in all the other outputs. There are individual reset filter points of at the top of page a global reset.

The list of quarries has a blue line under the name of the quarry. The length of this line indicates the number of readings in the analysis that the report represents. Obviously the longer the line the more reading and more reliable the assessment.

If it appears sluggish then the server is reaching the limit on the number of people that access it and if it stops then the server is at capacity and ‘Computer says No!’ to quote a classic comedy series.

The value of the tool is the ability to see beyond your contract. So if there were quarries operated by others that give a better result we should be considering its use if the performance of existing aggregate is not meeting design expectations. 

Note

Remember that the data is drawn from RAMM. Results in RAMM are not sanitised and if a reading is low due to contamination it still remains a value but affects the standard deviation of the graphs. You can adjust the %age included in the reading at the top of the first graph. 

Support

For use and support on the performance aggregate tool please contact your local Asset Integrator or email TransportServicesOPPPTechnicalAdvice@nzta.govt.nz.