The charges that reflect the loss in service value of the transit agency's assets. Depreciated items have a high initial cost and a useful life of more than one accounting period. In order to account for the reduction in value (usefulness) of this type of asset, a portion of the cost is expensed each year of the asset's life. Depreciation and amortization include the depreciation of the physical facilities such as: revenue vehicles; facilities (including buildings, equipment and furnishings), passenger stations, and parking facilities, etc.