Functional road classification systems or road hierarchies are widely used in all aspects of traffic planning, traffic operations and road asset management. Considerable effort should be invested to keep them current, relevant and consistently applied within and across jurisdictions. With increasing emphasis being placed in New Zealand on cost-effective and equitable management of transport infrastructure and sustainable transport systems, road hierarchies should be better designed and implemented than is currently the case.
This paper identifies and compares a variety of functional road hierarchies from both the national and local sectors, including those used by Land Transport New Zealand, Transit New Zealand and six metropolitan areas. Many of the systems analysed use traffic volumes as indicators of road class but widely different definitions exist. Besides traffic volumes, the hierarchies have a number of criteria used to classify roads, although these are not explored in any detail in this paper.
The paper makes a case for reviewing New Zealand's various functional road hierarchies to develop a road hierarchy for application across the country. Rational transport planning and traffic engineering decision making will be greatly enhanced by such a move. New Zealand is a small enough country that a national road hierarchy could be developed with relative ease, whereas other, larger countries will have much greater difficulty aligning the systems of many more agencies.
So are we ready for a national road hierarchy? There is no better time than now!
Transportation Conference, Tauranga