The AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing, 2026 edition, collects specifications, practices, and test methods used in highway materials construction and acceptance. Part 1 contains standard specifications and standard practices, covering materials such as fine aggregate for hydraulic cement concrete, mineral filler and fine aggregate for asphalt mixtures, metallic-coated steel wire rope for guardrail, deformed steel bars for concrete reinforcement, corrugated steel pipe, portland cement, and concrete sewer and culvert pipe. Part 2 contains standard methods of test for sampling and testing these materials. Part 3 presents the AASHTO Provisional Standards, which allow practitioners to use test methods and practices early in their research and development phase. The edition carries numerous revisions to individual sections, tables, figures, and notes across the three parts. It serves materials engineers, laboratories, and agency acceptance programs working with highway construction materials.