D2a Whats with the new U.S. Routes?
New roads, US 400, 412 and 425 were commissioned earlier this decade. They are out of the original numbering system (instead they use a new numbering sysem multiplied by 12.5), but were included because those routes carried a LOT of intercity traffic. US 400 and 412 are NHS/ISTEA High Priority Corrdiors (see I3). The numbers were chosen based on mutiples of 12.5, meaning the next new US route will be 437.
