TRB's National Cooperative Highway Research Program (NCHRP) Research Report 854: Guide for Identifying, Classifying, Evaluating, and Mitigating Truck Freight Bottlenecks provides transportation agencies state-of-the-practice information on truck freight bottlenecks using truck probe data rather than traditional travel demand models. The report embraces a broad definition of truck freight bottlenecks as any condition that acts as an impediment to efficient truck travel, whether the bottleneck is caused by infrastructure shortcomings, regulations, weather, or special events. The comprehensive classification of truck freight bottleneck types described in this report provides a standard approach for state departments of transportation, metropolitan planning organizations, and other practitioners to define truck freight bottlenecks and quantify their impacts. This project produced the following appendices available online: Appendix A: Selected Details of State-of-the-Practice Review Appendix B: Short Summaries of Selected Case Studies Appendix C: Data Quality Control Examples Appendix D: Additional Performance Measure Discussion and Analysis Procedures Appendix E: Truck Bottlenecks and Geometrics