Friday, June 22, 2007

BART in they asked

OK, Chronicle has this poll (today) and article about BART's future...far future. Poll had people picking specific extensions they'd like to add. There are talks of adding another Transbay Tube. Sure, that's fine, but I'll probably be long retired by then, let's hope.

What I want is more frequent trains. I dont want to wait for 15 or 20 minutes for the next train to arrive. In Europe, I'm able to just hop onto a train within 3-5 minutes, at any time. Maybe those trains were serving a smaller geography but still, that's mass transit. That's how BART should be too. It's ridiculous that at 5:30pm, while everyone is rushing home from SF to the East Bay, people have to wait 18 minutes for the next Fremont train, for example. Sure, they can transfer, but transferring doesn't shorten the trip or the wait in the end.

My ideal BART experience is getting on and off a train without waiting more than 3-5 minutes...that means in the morning, when i get home from work, to and from ball games and airports. Can BART deliver that?


Eric said...

I don't think it's reasonable to think that headways on every line should be 3-5 minutes. That can be pulled off in Tokyo or New York, but those are very dense, highly urbanized areas -- much more so than really anywhere BART goes, SF included. However, thanks to all the track shared by multiple lines, waits can be about that short if you're only traveling in the core part of the system, between MacArthur and Daly City. That doesn't help you specifically for traveling to Lafayette, but it does help lots of other people.

Another issue here is that a single transbay tube, currently used by 4 lines, can only take so many trains, as they do need to be properly spaced -- not sure how much exactly, but I would guess that at transbay tube speeds, probably around a couple minutes per train. Which means that the smallest headways you could achieve for any individual line would be more like 8-10 minutes, rather than 15 minutes. So, yes, I think the every 3-5 minute goal for any individual line is hopeful, as long as we have only one set of tracks everywhere.

However, adding a second transbay tube would allow a more even distribution of the transbay lines. If an additional SF tunnel is added to go down Geary, you could route 2-3 lines per transbay tube, rather than the 4 we have now, giving extra capacity to further shorten the headways.

Anonymous said...

BART afit prop at the timr of the bond issue touted trains every 90 seconds. unfortunately, although such headways were then possible w/ 50's technology in Chicago's State St Subway, BART "space age" computer wizardry can't do better than 2 minutes. Thus the best possible w/ four lines is 8 minutes. Mind you if that existed ALL DAY most of us would find it good enough

Anonymous said...

To improve headways, BART attempted to use a technology that did not work. There are technologies that allow 90 second spacing, and, once BART gets done with the litigation of the old contract, that technology can begin.

Another limiting factor is the dwell time at Embarcadero. Three door cars will make that quicker. Another solution would be to have some commute trains skip Embarcadero and stop at Montgomery, etc.

When Muni links Powell with the Third Ave line, look for the SOMA area to boom, and you might see trains that go directly to Powell, skipping the first two.

Eventually, 24th street is supposed to become the turnback point for the Fremont (San Jose) trains, and you might see 7.5 minute service on part of the Concord line (say 24th to Pleasant Hill) during most of the day.