Transportation departments are beginning to recognize that adaptation for climate change must become an integral part of their planning efforts. However, staff members frequently lack the adequate local data, training, and guidance needed to begin adaptation planning assessments. As a result, planning for adapting to climate change has remained generally abstract and lacks the specificity needed to identify potential system vulnerabilities, assess risk, and prioritize responses. This report outlines a geographic information system–based method with which transportation departments can assess vulnerabilities to climate change in their multimodal surface transportation systems. The city of Portland, Oregon, is used as an illustrative case study. The proposed method allows for preliminary vulnerability identification, prioritization, and impact assessment and can also be used as a basis for more advanced analysis and scenario testing. This research also identifies and describes data gaps and other barriers to climate change adaptation planning for surface transportation.