Comments on: A Problem With Buses

By: joshuadf

joshuadf — Wed, 30 Nov -0001 00:00:00 +0000

Hey, what a great project for UW Oceanography to work on with local transit agencies! I’m only half joking, there are some very smart people who work on things like mathematical models of halibut migrations.

By: serial catowner

serial catowner — Wed, 30 Nov -0001 00:00:00 +0000

I imagine that in the future this all will come together, with modeling based on fluid dynamics and migrations, and they will look back on how we do things now the way you would look at the old scientific or engineering calculator.

You’ve probably never seen one of those things- they had some at my first college as museum pieces. They looked like the old push-button-and-crank calculators shopkeepers used to use, but they were about ten times as wide and long. You could enter something like ten values to the 14th decimal point by pushing the buttons, then you reached over and pulled the crank, and, hey presto! out came the answer.

Cutting edge stuff, back in 1936.

As to the practical implications of improving predictions about how many people want to be at work by 8 in the morning, I’m a little hazier on that….

By: Matt the Engineer

Matt the Engineer — Wed, 30 Nov -0001 00:00:00 +0000

I don’t know that traffic waves cause bus bunching. Traffic certainly can cause it, but more often it seems like it’s a capacity issue. 12 people all show up a stop A just as a bus gets there. It takes a few minutes to load. Stop B has 14 people and a wheelchair. It takes a few minutes to load. Meanwhile, nobody was at stop A for the next bus, an one person with an ORCA card was at stop B. By stop D, the first bus is quite late, and more and more people are waiting at each stop. They all cram on to the first bus, and the second (nearly empty) bus is forced to wait.

As an aside, from the linked article: “the model could help engineers design roads with enough capacity to keep traffic density low enough to minimize the occurrence of such jams.” Great – I predict a few more hundred billion dollars in road spending comes from this study.

By: Frank

Frank — Wed, 30 Nov -0001 00:00:00 +0000

… and that problem is exacerbated by the trackless trolleys in Seattle — they can’t leapfrog each other, so the front bus in the backup just gets more and more overloaded, while the one in back just trots along empty right behind it.

By: serial catowner

serial catowner — Wed, 30 Nov -0001 00:00:00 +0000

Well, this is a problem that could certainly be solved by having a dispatcher and the drivers figure out when this is happening, and changing the destination sign on the leading bus to “Full”.

In fact, you might imagine that each bus has a GPS transponder that shows the location on a dispatch board, so the dispatcher could see the situation even when the driver of the lead bus couldn’t.

Probably another unattainable dream.

By: Frank

Frank — Wed, 30 Nov -0001 00:00:00 +0000

GPS-enabled Metro buses are coming soon — sooner than you might think.

By: Matt the Engineer

Matt the Engineer — Wed, 30 Nov -0001 00:00:00 +0000

I would imagine leapfrogging doesn’t happen much at diesel buses either. It basically means skipping a stop, or having the full bus wait at a stop while being passed (not pleasant for those crammed inside in an apparently stalled bus).

By: joshuadf

joshuadf — Wed, 30 Nov -0001 00:00:00 +0000

48s leapfrog fairly often on 15th Ave NE during evening rush hour. There are bus stops every 2 blocks and there’s always a bus traffic jam (43, 44, 48, 49, 271, and several commuter routes all stop at each stop). It’s also the only place I’ve ever seen four 48s bunched! (One was an 48X.)