This Guidance Manual provides design engineers and the public with practical technical information related to the beneficial reuse of scrap tires. This Guidance Manual is an outcome of the 1991 Scrap Tire Recycling Act, adopted by the Maryland General Assembly and constitutes Maryland Environmental Service (MES) efforts to promote the reuse of scrap tires. The focus is on the use of tire derived aggregate (TDA) in civil engineering projects in Maryland.This manual provides a review of Federal and Maryland regulations on scrap tires; presents key engineering TDA properties reported in the literature; and provides a discussion of the application of TDA in landfill, retaining wall, embankment, septic system, and other civil engineering projects. For each of these applications, general material requirements and performance considerations are discussed.