GM Seven Sisters Track
This project, built at the General Motors Corporation proving grounds in Milford, Michigan, was constructed in the fall of 2011. This project involved the reconstruction of the existing Seven Sisters Track and Access Road. The existing track with its seven unique curves with varying rates of superelevatation was removed and over 2900 tons of 22A Gravel was placed as base. A grader equipped with GPS was used for fine grading the base prior to asphalt placement. The existing access road was pulverized and shaped prior to asphalt placement.
Upon completion of the asphalt over 14,000 square yards of slopes were graded and restored. The complexity of this project came from the varying cross slopes throughout the track and time of the year that it was constructed. The nearly 2,000 feet long track involved superelevations of 1.5 percent to 7 percent with transitions in between. The project was built over a two week period and was challenged by November rains and cool weather.