In 1993, two hot-mix asphalt and four whitetopping overlay test sections were constructed on low volume TH 30 in southern Minnesota. A study was undertaken to examine the performance and costs associated with the test sections after nine years of service. The field testing and evaluation are described, and the costs incurred through 2001 are tabulated. The hot-mix asphalt overlay test sections are performing up to their design expectations. Both hot-mix asphalt test sections have had routine preventative maintenance applied to them, adding to their long-term cost of operation and ownership. The whitetopping test sections are performing very well at the midpoint of their design life of 20 years. Most distresses to date are related to poor construction and materials, rather than inherent design features. Some random longitudinal cracking has occurred in areas of the whitetopping control section. The doweled test section has numerous distressed transverse joints caused by dowels near the surface of the slabs. There is virtually no faulting of the transverse joints, and the ride quality has stabilized. No maintenance has been performed on the whitetopping sections through 2001. As of 2002, the most economical overlay design in this study is a 6 inch thick bonded whitetopping. Based on recent observations, it appears whitetopping is a good performing and economical rehabilitation option for low volume roads in Minnesota.
