2011 Green Book

Until FHWA formally adopts the 2011 Green Book through formal rulemaking, the 2001 Green Book is the adopted standard (as specified in 23 CFR 625) for construction and reconstruction projects on the National Highway System. Until the 2011 Green Book is formally adopted, it should only be considered guidance. As we have done in the past, we encourage divisions to not require formal design exceptions for the thirteen controlling criteria on these projects if States choose to use values from the 2011 Green Book that are less conservative than in the 2001 edition.