Watch highlights from Moody’s Mega Math Challenge 2012, where thousands of high school students from the Eastern U.S. created mathematical models to determine the best regions in the country for establishing rail lines as part of a revived High-Speed Intercity Passenger Rail (HSIPR) Program. The regions were ranked based on estimates of ridership numbers over the next 20 years, and costs of building and maintenance, in addition to the effects such rail networks would have on American dependence on foreign energy.