In 2008 the FHWA added new regulations to the MUT CD regarding minimum levels of retroreflectivity for traffic signs.This action changed the guidance relating to maintaining minimum levels of retroreflectivity from a recommended practice to a required activity.The new regulations went into effect at the national level in January 2008 and were added to Minnesota’s Manual in February 2008. The adoption of these new regulations means that all agencies are required to adopt a method of maintaining their signs by January 2012 to have all ground mounted signs meet the new requirements by January, 2015 and all signs meet the requirements by January 2018. This Handbook is intended to provide local agencies with information to help maintain the traffic signs on their system of roads. The Handbook identifies maintenance methods, provides an overview of estimated annual maintenance costs and includes a discussion of policy development, conducting engineering studies and a summary of what is known about the effectiveness of traffic signs. A key part of the message is that estimated costs associated with meeting the new requirements far exceeds the typical sign maintenance budget for most local agencies and that the only part of the cost equation that the agencies control is the size of their inventory. As a result, agencies are encouraged to determine what they can afford for a sign maintenance budget and then take the necessary steps to adjust their inventory to match.