Which type of design standards is bound in a separate set and can be applicable to various projects?

The selection of Roadway and Traffic Design Standards is appropriate because these standards are specifically developed to address various aspects of roadway and traffic design, ensuring consistency and safety across different types of projects. They provide guidelines for geometric design, traffic control devices, and other roadway features which can be applied universally to multiple project types, ranging from highways to local streets.

Roadway and Traffic Design Standards have a broad application, making them vital for planning and designing effective transportation systems. These standards are accessible in a separate set so that designers and engineers can refer to them as needed for various projects without having to sift through project-specific documents. Their separate compilation helps ensure that all relevant parties can easily find and utilize the information, thus enhancing efficiency in the design process.

In contrast, structural design standards, while critical for specific infrastructure projects, are often more tailored to particular types of constructions, such as bridges or buildings, and may not have the same broad applicability across diverse projects. Environmental impact standards are specifically related to assessing the ecological effects of projects, which are project-specific rather than broadly applicable to all design endeavors. Lastly, safety design standards, while essential for ensuring user safety, are often integrated within other design frameworks and may not constitute a separate set applicable to multiple project types.