How often must annual upkeep of $75,000 be included in total cost calculations for the bridge?

The correct approach in this scenario is to account for the annual upkeep of $75,000 every year in total cost calculations. This is because maintenance costs are recurring expenses that contribute to the overall financial responsibilities associated with the bridge's lifecycle. Each year, these costs need to be included to provide an accurate representation of the total cost involved, ensuring that budget allocation and financial planning reflect ongoing operating expenses.

Annual maintenance is crucial for preserving the structural integrity and usability of the bridge, and overlooking these yearly costs could lead to underestimating the financial commitments required over the lifespan of the asset. By incorporating yearly upkeep into cost calculations, one ensures that all necessary expenditures are accounted for, allowing for better financial forecasting and management.