Applying the framework (continued)
Transport: Development of state highway classification system
Availability of asset performance information about state highways
NZTA and its predecessor organisations have for many years collected and published data for many performance metrics in relation to the state highway network. Much of the data are publicly available online through the Transport Monitoring Indicator Framework, at http://www.transport.govt.nz/ ourwork/TMIF/Pages/default.aspx
The published indicators include utilisation statistics (broken down by road type, vehicle type, urban/rural and region); network reliability in terms of congestion; and quality of the road surface. At the aggregate level, such indicators have informed decision-makers about maintenance, congestion and safety pressures on the network. At the detailed level, they have informed network management decisions by the NZTA such as where to put passing lanes and how to optimise timing of maintenance.
Why develop a state highway classification system?
Resources available for state highways will always be limited. Classifying state highways means we can group roads with similar functions together. This is a necessary first step to ensuring over time that roads with similar functions have similar service levels, and provides a useful framework for targeting resources to areas of greatest long-term needs.
In February 2011, NZTA published a draft state highway classification system, available at http://www.nzta.govt.nz/consultation/classification-system/
A classification system for the state highway network can contribute to the Government's priority of increased economic productivity and growth by:
- helping NZTA align planning, investment and operational activities for the network to address capacity constraints, and
- signalling to road users the levels of service they can expect (over time) on highways in each category of the classification system.
The draft classification system uses available data, especially on the extent and type of utilisation, to categorise highways in the state highway network based on their national, regional or local roles, and their functions within the network. Criteria that determine the classification of a highway include its functions in moving freight (to and from ports), people (to and from places of work, tourist attractions and airports) and securing links between major population centres.
Once consultation is completed, the classification system will inform the process for determining appropriate levels of service for each category of the network. Aligning service levels according to each road's function means we can signal long-term performance expectations to highway users and the wider community.
Indicative service levels will be included in the draft State Highway Network Strategy which will then go out for public engagement.
The indicative service levels will inform future State Highway Asset Management Plans. These describe the appropriate technical service levels applicable for each road according to its use; for example, whether median barriers or other safety improvements features are suitable for the given road.
Congestion and safety measures are collected for much of the network. Congestion and safety are not among the criteria for the classification, but show where there are deviations from the expected service level on parts of the network and are therefore taken into account when assessing the need for investment.
Maps of specific attributes of state highway usage are available online using the link above.
