The RPTA operates a customer service, marketing and long-range transit planning operation from headquarters in downtown Phoenix which is shared among all Valley Metro member cities. A few routes which operate within several member cities have their funding and operations shared between those cities. Some RPTA funding is used to augment service provided by the member cities (this is expected to increase over the next several years due to a 2004 voter approval of an extension to the original 1985 sales tax for transit funding). The city of Phoenix alone operates 73 percent of all Valley Metro routes (several of which also serve suburban cities).