A 2004 trial of the Otta seal technique in various locations in New Zealand showed that it may be a better option for dust minimisation and, based on life cycle costing, could be a lower-cost option when compared with traditional short-term dust palliatives.
A research trial was proposed to, and funded by, Land Transport New Zealand to set up four trial sites around New Zealand, to compare the performance and life cycle costs of the Otta seal with waste oil and other dust minimisation techniques.
In spite of environmental issues, waste oil was used in this research, as it has been widely regarded as the most cost-effective dust minimisation treatment for unsealed roads in New Zealand, and its use is still allowed by a number of territorial local authorities throughout the country.
The research concludes that the Otta seal is the most effective dust minimisation technique available, and the most cost-effective treatment based on life cycle costing.
The report also concludes that the use of waste oil as a dust minimisation treatment should be banned.
A guideline for the construction of these seals was developed as part of the research.
Keywords: dust, life cycle, Otta, palliative, performance, seal, suppression, technique