What is the department's manual that provides codes for different materials used on DOTD projects?

The most appropriate answer is the Materials Specification Manual. This manual serves as a comprehensive guide for the different materials used on DOTD projects, providing specific codes and standards that govern the selection, testing, and utilization of these materials.

It is essential in ensuring that all materials conform to established criteria, enhancing safety, performance, and durability in infrastructure projects. By having a systematic approach to material specifications, the department can ensure consistency and quality in construction practices, allowing for efficient project execution.

The other options, while related to materials and construction practices, do not specifically serve the same purpose of providing detailed codes for materials. The MATT System Field Handbook typically focuses on measurement practices, the Material Testing Guide outlines how materials should be tested rather than giving specifications for them, and the Construction Code Manual generally deals with regulatory compliance for construction methods rather than the materials themselves. Thus, the Materials Specification Manual is critical for understanding and applying the correct materials in DOTD projects.