The Federal Highway Administration (FHWA) conducted an international review to study how international transportation agencies are addressing issues related to adapting highway infrastructure to the impacts of climate change. The review involved transportation agencies from Australia, Canada, Denmark, Korea, New Zealand, the Netherlands, Norway, and the United Kingdom. The review elicited information on adaptation issues associated with all aspects of the transportation project delivery process. This synthesis report highlights the state of the practice of how transportation agencies are addressing climate adaptation through the following: adaptation frameworks/strategies; climate change risk assessments; selecting adaptation measures and strategies; long range planning and land use; changes in design standards; maintenance and operations; asset management; and research. The information collected during the review and presented here is relevant to transportation planners, asset managers, design engineers, and policy-makers.