What is the primary purpose of a geotechnical investigation in highway construction?

The primary purpose of a geotechnical investigation in highway construction is to evaluate subsurface conditions and inform design. This process typically involves collecting and analyzing soil and rock samples, as well as assessing groundwater levels and other relevant geological factors. Understanding these subsurface conditions is crucial for determining the strength, stability, and behavior of the ground under the proposed highway.

By having detailed information about the soil and rock characteristics, engineers can make informed decisions regarding the design and construction methods to be used, ensuring that the highway will be safe, durable, and effective in serving its intended purpose. This investigation also helps identify potential issues that could arise during construction, such as the need for deeper foundations or special drainage solutions.

The other options, while important considerations in the overall project planning and execution, do not capture the primary role of geotechnical investigations. Economic feasibility relates more to budget and funding assessments, aesthetics pertains to visual design elements, and traffic management focuses on planning for vehicle flow during construction. None of these aspects address the fundamental requirement of understanding subsurface conditions that underpin effective highway design.