From Portland Afoot

Operating expenditures generally refer to the continuing costs of doing business, such as staff salaries, facility and vehicle maintenance, and the purchase of raw materials and goods sold. A government budget is generally divided between capital expenditures and operating expenditures.

In the case of TriMet, most capital expenditures in a given year are related to rail and rail station construction, while most operating expenses go toward paying the system's employees to provide service. TriMet has relied heavily on Federal Transit Administration grants (largely the New Starts program) to cover the capital expenses of building the MAX system. These grants cannot be spent on transit operations without a change in federal law.