12
Jul

2010

Thick Around The Middle

Post by Steven Dale

Have you ever noticed that the front-most and rear-most cars in a train are typically underused – indeed, sometimes empty! – even at the height of rush hour? Smart and experienced transit riders walk those extra 50 meters to the end of the subway platform and get a seat, while everyone else just crowds (miserably) into the middle.

Same thing with buses, streetcars and trams. Front’s packed solid, back’s often empty. What percentage of capacity does that empty space represent? Five percent? Ten? Twenty?

It’s illogical and irrational. But then again, so are humans.

When transit agencies report the offered capacity of a line, they report what’s theoretically possible assuming every square inch of space is taken up and every seat is filled. They assume that every space on the train is thick instead of assuming it’s just thick around the middle (or front).

It’s a poor assumption which ignores the fact that humans use transit, not equations. Transit engineers and planners, unfortunately, don’t seem to be taught that.

Include the human factor, and suddenly your transit line is probably carrying far fewer people than you actually think.

I don’t believe there’s a name for this phenomenon, but there should be. Any suggestions?



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Comments

  1. matthias
    July 12, 2010 – 1:44 am
    Transit planners are well aware of the problems and took various attempt to lessen the problem. A simple solution is to place station exits at different heights of the trains as most people are lazy. Thats way most modern urban trains are walk trough design where you can walk and see trough the whole train. So that everybody can find his seat. On Older subways every wagon was an unit of itself and people could change to another wagon.In Japan even if two train sets are coupled together a gangway will be established within seconds to allow passengers walk trough the train. Older trams/streetcar where coupled together while newer are alway long articulated train sets. Even buses used to have hangers while now we have articulated buses.
  2. Steven Dale
    July 12, 2010 – 2:15 am
    Matthias, They may know about the problem, but they havent really done anything to solve it. Walk through trains are nice, but theyre no solution. Once people enter a vehicle and choose their position, theyre unlikely to move. That eventually leads to bottlenecks and jams within the train and peoples ability to move throughout the vehicle ceases.
  3. LX
    July 12, 2010 – 3:29 am
    I agree with matthias, I don't see it that often that front or rear part are empty. I experienced a couple of cities and their infrastructural solutions and the use of capacity was almost always pretty even. And I found the solution like Matthias mentioned mostly in solutions by the transit planners to place entries and exits of stations well located. The most interesting part in this whole thing is that people like to avoid each other by keeping up a distance. I believe it was in public around 1.5 meter that we walk on by others, even though we would never collide or else by 0.5 meters. If you are a little faster (by bike for instance) you will find it more comfortable to have at least 2 meters or more. Same for the other side. People won't stop if you cycle around them with enough space, but with less the will stop or even say/shout something. With seating it's a little different. Some people try to search connections to people they think are okay, but in general everybody wants his/her safe place. You may have noticed the "thing" with benches in parks. Someone will sit on it, probably so that there is like 80 % of the bench free in one direction. Well then another one comes with another 20% and all out of the sudden a 2.5 meter bench is theoretically 100% used by 2 people using about 40 %. The interesting part in this case again is, if someone REALLY wants to sit there too, he/she will ask and it will be okay. Same in the buses and similar. We are used to have our own private safe places - extra seats around us and we will search those places to get our comfort. But we accept in order to get somewhere else faster to reduce this level of environmental comfort for a better level of economics (hope you understand what I'm saying since english isn't my mother language). Researchers in the automobile industry found out, that by now - when we all are getting made more and more used to e-cars it will be okay in future to NOT have an electrically operated window regulator - again. Like until 20 years ago when you had to pay extra (well yes by now you will have to pay extra too in some occassions but basically it is standard). I was going 3 hours by the best and fastest train of my country by sitting on my own bag because all seats were full and I was happy to reach my point as fast as possible. In highly developed countries it is crucial that infrastructure works by times announced. If your train departures too late you will miss your appointment. Same for the others to meet you. But that's why business in middle east is different to business i.e. in europe. You expect those things to happen and in other areas you expect those things NOT to happen, due to the price you paid or the whole setting of service and responsibility. Point being: I feel like there is plenty of space we are wasting. Well trains like you know from movies of india shouldn't be the aim, but I'd rather use the train instead of my car to reach my destinations when prices would be fairer regulated. Though I think there will come a time again for public transportation, especially for trains. http://www.mindset.ch/?language=en it's a link of a reengineered e-car. so not using a common car and putting in an electric motor. just take a look at the tires ;)
  4. Dave in KY
    July 12, 2010 – 4:06 pm
    My only workaday experience with rail was on SFBay's BART heavy rail system. People crowded towards the middle because different trains had different numbers of cars, and if you're standing at a doorway for car #10 when a 6 car train arrives, you are going to have to RUN the length of 4 subway cars in 20 seconds in order to get on board. That's impossible. So a better strategy is to board near the middle. They could easily improve this by simply saying the number of cars in the train on the LED displays (which they actually do), and articulating which parts of the platform would catch how many cars (which they don't do). It doesn't have to be a solution understandable to all, if only 20% of the ridership is smart enough to figure it out, that's enough to balance the load fine.
  5. Matt
    July 12, 2010 – 6:12 pm
    There was this recent idea from Barcelona that was picked up on in a few places of the web. http://4-id.org/blog4id/?p=163 Graphic displays show how much space is on each carriage. It doesn't look inexpensive though.
  6. Dave Brough
    July 13, 2010 – 9:11 am
    Figures lie, liars figure. Go figure Steven: “When transit agencies report the offered capacity of a line, they report what’s theoretically possible assuming every square inch of space is taken up and every seat is filled” Not only that, they use 'last mile' figures, omitting the inconvenient truth that from the first station clear through to that last mile, capacity is never remotely realized. Also omitted is the fact that for the rest of the day, you could swing a dead cat by the tail in just about any transit vehicle in the world. But it takes the same amount of effort (driver, fuel, roadway wear and tear, etc.) to get the vehicle to that last mile scenario. I recently asked Vancouver BC's transit service to support its advertising claim that its brand spanking new $2.1 billion ($200 million/mile) Canada Line could carry 15,000 passengers per hour and how this equated to 12 – 13 freeway lanes in a single direction. (In case you didn't know, this stat is 'standard' with just about any transit agency). Vancouver replied: “An arterial city road has the capacity for approximately 1,000 vehicles/hour/lane. Assuming an occupancy of 1.2 persons per car and five lanes in each direction, the road could carry 6,000 people per hour per direction. The design capacity of the Canada Line system – 3-car trains with 500 passengers each, running every two minutes - is 15,000 passengers/ hour/ direction, which would equate to 12-13 lanes of cars in a single direction at typical occupancies." Here's what they're saying: “No matter that even the smallest car has 5 seats, we're counting 1.2, because that's the average. And no matter that roads can easily handle 2-second headway, we're using 16-seconds between vehicles. And forget that our present system has only 200-seats per train-set and 3-minute headway, we're going to use 'design capacity' with three 100-seat cars with crush load of 500 passengers. We'll conveniently ignore the fact that we're only talking peak rush and the 'last mile' factor where, indeed, we theoretically can get those peak crush loads, and for the rest of the day, they're virtually empty” My response went like this... “Since you're taking the liberty with design capacity under ridiculously-optimum last mile conditions, what's good for your goose is good for my gander, so instead of 1.2 seats and 16-second headway, let's use articulated buses at crush capacity of 150 passengers/unit and headway of 3 seconds: 150 pax x 20/min x 60/hr = 180,000 ppdph per lane! And since you're allowing me 12 lanes, let's see, 180,000 x 12 = 2,160,000 ppdph! That's what I call 'fightin' fire with fire'
  7. Steven Dale
    July 15, 2010 – 1:13 am
    Matt, Probably isn't inexpensive, but let's think about it this way: What's the cost of adding vehicles/drivers to make up for that lost capacity? Is that more expensive than such a technology? Has this ever been implemented? I don't know how well face-recognition would work in crowded rush hour. I think an easier way to do it might just be a system where each individual car can be weighed which should give a pretty decent approximation of how many people there actually are (at the same time, I have no idea what I'm talking about here, so that idea could be orders of magnitude more expensive). Or . . . we start implementing technologies that involve vehicles that are 50 metres long. Gondolas, maybe?
  8. Steven Dale
    July 15, 2010 – 1:14 am
    Dave, Agreed. Whatever the solution is, it's something that should at least be addressed/acknowledged.

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