TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 505: Current Practices and Guidelines for the Reuse of Bridge Foundations provides guidance on reusing bridge foundations, a sustainable option for many bridge replacement and rehabilitation efforts that can result in time and cost savings as well as reduced mobility impacts and environmental benefits. However, foundation reuse presents significant challenges, including uncertainties in existing foundation condition, remaining service life, and capacity. This synthesis documents current practices and guidelines used by transportation agencies for the reuse of bridge foundations.