Just like going up the Eiffel Tower in Paris or seeing the Empire State Building in New York City, no visit to this city is complete until you try to ride the cable cars at least once. As far as being a practical mass transit system or a good way to get from Point A to Point B in San Francisco, they leave much to be desired.
After visiting San Francisco this past March, here is my two cents on the cable cars. First, riding them is extremely expensive at $6 each way (regular city buses and trains cost $2). We had the city pass, which got us unlimited rides for a seven day period and it was so much easier to flash our pass at the cash collector on the cable car then dig out the cash. Highly recommend this option. Another option without buying the city pass is to buy a Muni pass.
Second, even though we were not in San Francisco during a crowded time of year, there was always a line for the Powell lines. We even tried riding the Powell lines on a Sunday morning at 9:30 and still had to wait about twenty minutes to get on. While waiting for the Powell line cable cars at Powell and Market, there was no separate line for the Powell/Hyde or Powell/Mason line. It seemed to me that you just got on whichever cable car pulled up. Since the Powell/Mason line ends up in a different area than the Powell/Hyde line this can be kind of annoying.
Third, don't count on getting on any of the Powell lines at a stop different from the beginning of the line at Powell and Market. They just about fill up the cable cars at the beginning and usually have a very limited amount of room to add new passengers. Since most people are riding them to the Fisherman's Wharf area, very few people get off to add extra room. Somebody told us the traffic island for the cable car stop next to Union Square is called "Fantasy Island" because nobody is able to get on the cable car at this stop even though the people there think they can get on.
Finally, the best way to avoid all of this madness and to get a coveted spot on the outside of the cable car is to ride the California/Van Ness line. There was never a line while we were there for the California cable car and the cable cars on this line were never full. If you start at the financial district on the California line, you can ride it to Chinatown, get off, explore Chinatown, and easily get back on to ride it to the top of Nob Hill.
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