San Diego's metropolitan area is huge and sprawling. If you can afford it, it's best to rent a car.

By bus

San Diego does offer bus service to almost all parts of the county. If you will be mainly in the areas around downtown, the bus will be quite suitable. The fare is normally $2.25 and $2.50 for express busses. All downtown buses intersect with Broadway St. at some point. During the day all kinds of people will be taking the bus. At nights some people might feel a little less comfortable, but generally not unsafe on the main parts of downtown. The Metropolitan Transit Authority (MTA)  has offices in downtown, on Broadway St.

By trolley (tram)

San Diego offers a trolley service, mainly for tourists and people living in the southern and eastern parts of the city that need to get to downtown areas. There are three trolley lines: blue, green, and orange. Blue operates from the US-Mexico border to Old Town, with service during rush hour to Qualcomm Stadium, where the San Diego Chargers play. The green line travels from Old Town past SDSU to Santee. The green line will also take you to popular shopping destinations in the Mission Valley area. The Orange line connects the eastern cities of El Cajon and La Mesa with Downtown. Generally not as usable for tourists except for getting around parts of downtown. Bus and trolley transfers are interchangeable. There's no formal system to check if you've purchased a ticket, but there are trolley guards that may come around and ask to see your ticket. The fine is normally around $150 for not having a ticket, although sometimes (not recommended) you can talk them into simply letting you get off at the next stop and purchase a ticket. A $5 all day pass is available, as are 2 and 3 day passes, valid on both bus and trolley.