The 20-Columbus. Remember? That new trolley line, along with a rerouting of the 9x, was North Beach's consolation prize for losing the 15-Third, eliminated when the T-Third light rail line deep-sixed it last year.

Well, the 20 -- which runs the length of Columbus Avenue into the Financial District between 9 a.m. and 4 p.m. -- isn't exactly overflowing with passengers. In fact, ridership is so low that the Muni is now considering dumping it altogether. The 10-Townsend is another local line that might get the ax.

These cuts are two of many proposals being studied by Muni as part of its Transit Effectiveness Project, which, if implemented, would result in the most comprehensive bus rerouting done in my memory. And I've been here a long time. There isn't a single line passing through or near North Beach (save the cable cars) that wouldn't be affected in some way. You can go here to view the proposals for individual lines citywide.

Meanwhile, here's a quick rundown (with .pdf links to the proposed new routes) of how things would look locally if TEP was implemented as things currently stand:

9x-Bayshore Express: The Fisherman's Wharf extension, added when the 15 was eliminated, would be cut.

10-Townsend: This line would be eliminated.

12-Pacific: Its current route north of Market would be altered. Instead of turning south onto the Embarcadero from Broadway, the 12 would turn south onto Battery Street, picking up that part of the discontinued 10-Townsend's route. South of SoMa, it would split into A and B lines; A running to the Navy Yard and B to Third and Palou.

19-Polk: Not a North Beach line, you say? Au contraire, mon frere. In perhaps the biggest new wrinkle in routing for the northeast corner of the city, the 19 would become a loop (or "circulator," in the new venacular), sort of like the old 42-Downtown Loop. You can see its impact on North Beach, picking up portions of the routes abandoned by the 9x and 20.

20-Columbus: We hardly knew ye.

30-Stockton: Would remain unchanged except for a possible extension into the Presidio from its northern terminus. East of Van Ness (meaning North Beach and Chinatown, mainly), it would run five minutes apart. As a regular rider of this line, I can tell you that two minutes between buses isn't enough.

39-Coit: The Union Street leg of this line would be eliminated. If you miss one, you might die of old age waiting for the next one.

41-Union: When I was a kid, this was a major northside line. It's been peak-hours-only for years now and I still don't get it. Now they want to shorten it even more, eliminating its run from Cow Hollow into Pacific Heights to the Presidio wall. The 41 would now turn back at Steiner Street.

45-Union/Stockton: Here's another stumper. This line, along with the 30, provides some of the most miserable bus-riding in Christendom. Right now its southern terminus is near the Caltrain Station. Here's an idea: Let's run it out to Potrero Hill.

For me, all transit in this area hinges on getting people through Chinatown. If they're really going to extend the 45's run out to Potrero Hill, then perhaps they'd also consider instituting a special 30 "Circulator," running in a continuous loop between Market Street and Washington Square. At least until they get that Central Subway built. Here's another idea (all mine): How about closing Stockton from Broadway to the tunnel to everything but bus traffic?

Whaddya think? The Muni says it would like to hear from people regarding these proposals and they're accepting your suggestions until June 15. Recommendations go to the MTA board in late summer. They want things settled and running by July 2009. Got something you'd like to say? You can call 311 or go to the website and weigh in.

Thanks to my friends at Muni Diaries for tipping me to this story.