The National Historic Covered Bridge Preservation Program (NHCBP) includes preservation of covered bridges that are listed, or are eligible for listing, on the National Register of Historic Places. It also advocates research for better means of restoring and protecting historic covered bridges, using advanced technology. Strengthening Historic Covered Bridges To Carry Modern Traffic is aimed at the highest form of historic preservation: maintaining the bridge not only physically, but also functionally. While the builder’s original form is preserved, the structure continues to serve as a real bridge and not a historical relic. The technology being investigated uses glass-fiber reinforced polymer (GFRP) products to increase the strength of the members with minimal increases in x-section. The study also looks at ways to mask the use of the GFRP components. This study is just the beginning of research on this topic. The concept will be refined and amplified in future projects. This book is intended primarily for engineers, contractors, researchers, consultants, bridge owners, and historic bridge preservationists to help them keep these historic structures in full service.