The economic haul length is determined by which cost factors?

The economic haul length is influenced by both borrow cost and haul cost, making this the correct answer.

Borrow cost refers to the expenses associated with financing the necessary equipment and operations, which is crucial for determining the most efficient and economical operation for transportation. It includes interest on loans and any other financial charges incurred when acquiring resources or funding for the project.

Haul cost, on the other hand, pertains to the actual expenses involved in the transportation of materials from one location to another. This includes fuel, labor, vehicle maintenance, and other direct costs associated with the hauling process.

Together, these two factors—borrow cost and haul cost—provide a holistic view of the financial implications related to the operation, enabling engineers to optimize transport distances and methods to enhance economic efficiency.

Other options do not encompass both critical financial aspects, which are essential for accurately calculating the economic haul length. For instance, solely focusing on haul cost would overlook the financial burden imposed by borrowing, and considering interest rates alone lacks the contextual framework provided by the comprehensive cost analysis needed for making informed decisions regarding haulage strategies. Thus, a combination of borrow costs and haul costs leads to a more precise determination of the economic haul length.