Though Phoenix does have taxis as well as a new and expanded light rail system (plus public buses), it’s much easier to get around in this city by car. Taxi fares are unregulated in Phoenix (except at the airport), so fares over $60 are not uncommon. And only the downtown areas of Phoenix, Scottsdale and Tempe are friendly to those on foot, so it is advisable to rent a car (make a reservation for a rental car in advance, especially from January to April). Roads in Phoenix are arranged on an 800-square-mile grid. Central Avenue is the main north-south grid axis: all roads parallel to and west of Central are numbered avenues; all roads parallel to and east of Central are numbered streets. If you choose not to rent a car, the light-rail system will work for exploring downtown Phoenix. Fares are $3.50/day and multiday passes are available. Phoenix runs a free Downtown Area Shuttle (DASH).
Valley Metro (602-253-5000) has more info.