NHTSA has to issue its new standards eighteen months before the model year for fleet. According to NHTSA report, in order to achieve this industry wide combined fleet of at least 35mpg, NHTSA must set new standards well in advance of the model year so as to provide the automobile manufacturers with lead time enough to make extensive necessary changes in their automobiles. The EISA also called for a reform where the standards set by the Transportation Department would be are "attribute based" so as to ensure that the safety of vehicles is not compromised for higher standards.