How much more expensive are underground circuits compared to overhead circuits?

Underground circuits are generally more expensive than overhead circuits due to several factors. The correct choice indicates that underground circuits can be approximately four times more expensive per mile. This higher cost can be attributed to the complexities involved in installation, which includes trenching, the need for more advanced materials that can withstand environmental factors, and the additional labor costs associated with deep underground work.

Moreover, the equipment and technologies required to monitor, maintain, and repair underground systems are typically more sophisticated and costly than those used for overhead lines. In comparison, overhead circuits have lower initial installation costs because they are simpler to set up and require less specialized equipment. The long-term maintenance costs can differ, but the initial expense for underground solutions accounts for their significantly higher pricing relative to overhead circuits.