During the late 1990s the system suffered from poor management and aging equipment, but recovered somewhat in the early 2000s. The system also runs a limited number of zero emissions buses on some routes. Most buses are diesel powered, but a few are electric trolleybuses powered by overhead electrical wires.
Fares are currently $0.35 for under 18 years and $1.25 for over 18. Faced with budget constraints during 2003, however, fares were scheduled to increase. Proof of purchase is handled through a transfer slip, either a flimsy piece of paper (buses and streetcar) or print on thicker, card-board-like paper (subway stations and a few outdoor stops such as San Francisco State University), all of which are randomly checked by police officers. Frequent riders can get a Fast Pass for every month. Combination options for tourists and Bay Area Rapid Transit users are also available.
Route information is available from any bus stop, Metro station, or by asking the driver or station agent.
Many newcomers and visitors confuse Muni with Bay Area Rapid Transit, as they share several of the same subway stations. BART is a regional transit system with its own dedicated tracks and trains. MUNI trains run underground in some of the same subway stations, but they are on different tracks at different levels. MUNI only goes within the city limits, BART has a very long range to suburban stations in other counties.