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This study investigates the cost effectiveness of conventional and alternative construction and maintenance procedures for unsealed roadways. The study was undertaken during 1987, 1988 and 1989.

Test sections of unsealed pavement were constructed on two unsealed roads within Rodney District, North Island, New Zealand. A material testing programme was carried out to evaluate the characteristics of the local aggregates, as well as testing alternative construction and maintenance procedures. The performance and maintenance requirements of the roads were monitored for roughness and maintenance costs.

The cost effectiveness of alternative materials, construction and maintenance procedures was evaluated from analyses of the roughness and maintenance cost records. The most cost-effective procedures were ascertained to be:

• use of secondary aggregates
• increased crossfalls (to 6–8%), and
• use of up to 10% clay as a binder.

Keywords: Aggregates, clay content, construction, costs, economic analysis, monitoring, New Zealand, roads, roughness, testing, unsealed