This guidance provides you with a revised list of research-proven countermeasures that supersedes the 2008 guidance. Through our collective efforts, many of the nine safety countermeasures in the 2008 guidance are thoroughly integrated into the options the States consider as they address their safety issues. However, some have not reached that level of wide spread application. Accordingly, some of the countermeasures from the 2008 guidance were brought forward with the new ones we’ve added. As you so successfully did with the 2008 guidance, we encourage you to advance these safety countermeasure options with your State DOT counterparts.