Feasibility Investigation of Upgrading Gravel Road to Otta Seal Surface: an Economic Analysis Approach

In the 1960s the Norwegian Road Authorities was looking for a surface treatment that was cost-effective, easy to implement, utilize local materials, impervious, flexible, durable, and easy to maintain. Field trials were conducted, and Nordic countries, as well as Africa, New Zealand and South America have experienced an increasing use of the seal. In the U.S., the use of Otta seal has been limited, due to lack of knowledge and of the empirical design approach associated with the technique. The only states that have completed Otta seal projects are South Dakota, Minnesota and Iowa. In order to determine the investment needed for this type of undertaking, the evaluation of a one-mile generic upgraded gravel road in Minnesota was conducted, in terms of the life cycle cost of surfacing and maintaining an Otta seal coated surface. The evaluation was carried out through deterministic and stochastic life-cycle cost analysis (LCCA). Minnesota was chosen for the case study due to the fact that historical bid and performance records of Otta seal in Iowa were not available. The results of the analysis showed that in most cases maintenance savings on their own are not enough of a justification for the investment, in spite of revealing that this was the case in some of the cases. In order to determine the optimal times for upgrading roads to surfaces covered with bituminous surface treatment (BST), another economic analysis was conducted, taking traffic volume into consideration for four counties in Iowa and Minnesota. These results showed that justifying Otta seal surfacing based solely on economic analysis might be possible for 15% of gravel roads.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 7p

Subject/Index Terms

Filing Info

  • Accession Number: 01711302
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Jul 19 2019 9:57AM