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Dec 06, 2010
Thought Experiments

A Thought Experiment: Turning Tables

Post by admin

A thought experiment:

Do we have a transportation supply problem?

I’d say no. We’ve got plenty of roads, plenty of transit and plenty of freeways. We do not have a transportation supply problem.

Image by flickr user joiseyshowaa.

(I’m well aware, of course, that there are certain large American and developing world cities that have slim to no transit, but for the sake of simplicity, let’s leave those out of the discussion for the time being.)

What we do have is a transportation demand allocation problem. We have too many people demanding transportation services at a single time. Too many people want to get from Point A to Point B during the hours of 7am – 9am and 4pm – 6pm.

Generally speaking, about 1/3 to 1/2 of all motorized transportation trips occur during those four hours. Basically, 33 – 50% of all travel occurs during a window of time that accounts for only 16.6% of the day.

That is a demand allocation problem. Not a supply problem.

North American restaurants face this problem constantly, but successful ones handle it with ease.

The dilemma restaurants face is this: Most diners like to eat at 7:30pm. That presents an enormous problem.

Restaurants have a limited supply of space. They only have so many seats, so many tables, so many burners, so many dinner plates, etc. And there is virtually no way to expand that supply. For a restaurant to make money, they have to reuse that supply over-and-over-and-over again throughout the course of a day. There is simply no way a restaurant to accommodate all the demand during one two hour period that begins at 7:30.

Because most restaurants assume a table will be used by a given party for around 2 hours, a 7:30 reservation means the table in question is basically booked for the night. For most people a dinner out at 5:30 is too early and 9:30 too late. (In fact, for the after-movie, after-theatre crowd, 9:30 is also too early.) If a 7:30 reservation is granted, the restaurant cannot “turn” the table.

If the restaurant is slow, this doesn’t present a problem. If the restaurant is busy, however, every “turn” that’s missed hurts the bottom line hard. Restaurants operate on extremely slim profit margins. Even high-priced, fine dining establishments are used to walking that fine line. For a restaurant to make money, they need to “turn” a table as many times as possible to maximize revenues.

Therefore, not everyone can eat at 7:30. That’s the rule.

That’s why when you call a restaurant asking for a 7:30 reservation, the Maitre d’ is likely to tell you he can take you at 6:00 or 8:00. Still want to show up at 7:30, just in case? Great! There’s space at the bar while we prepare your table! He’s not saying he doesn’t have room for your party at 7:30, he’s telling you he has room for your party as well as someone else’s.

He’s not doing it to annoy or irritate you, he’s merely shifting and reallocating demand to meet supply.

So the thought experiment is this: Do we need a Maitre d’ of Roads & Transportation?

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15 Comments

  • ant6n says:

    Is that the GoTransit perspective?
    I once read something that said that Go Transit gets something like 90% of their users go through Union Station in the rush hour direction. But that’s all that the service offers – one station in downtown, and rail service in rush hour direction on most lines – and planning that really tries to build the mostly densely packed CBD.

    My question is wouldn’t be about the speed that this restaurant can turn tables, but why they don’t have lunch specials and breakfast specials, why there’s no happy hour, no midnight snack? I want to eat at the transit restaurant at all times, in any direction.=

    • Steven Dale says:

      @ ant6n,

      I don’t know about Go Transit specifically, but that seems to be about right. And when you’re building capacity for all that demand at one single time, how is that supply used during off-peak hours? It’s totally wasteful.

  • ant6n says:

    Exactly. So that’s where better planning comes in. Polycentrual metropolis, mixed use areas – those ideas not only help to create more coherent/walkable communities (you get activity centers closer to where you live), but also create trips in all sorts of different directions spread more throughout the day.
    Urban planning and transit planning are intertwined, and both take years for the results to be seen. One way in which transport planning can help, though, is to offer more capacity as if the city was more polycentrual, and then hope that the urban form will follow. And the converse is the hope that this will relieve the unidirectional rush more than the attempt to increase capacity by squeezing the current system to the limit.

  • ant6n says:

    Btw, LinkWithin is a good addition to the blog.

    • Steven Dale says:

      @ ant6n,

      Re: LinkWithin. Glad you like it. Short term measure to help people access older posts. Definitely need a better long-term solution however.

  • Seth says:

    Its called private toll roads. Restruants invent a 100 ways to allocate resources effectively because they are privately owned. If you want to live and work down a popular road, either work non-regular hours or pay to use the road during its peak time.

  • Mono says:

    Technology has a way to fundamentally change the way we live our lives. As societal norms change, perhaps our transportation patterns will change as well. Telecommuting is something that wasn’t possible 10 years ago, but its a growing trend everywhere in the world now.

    • Steven Dale says:

      @ Mono,

      “Telecommuting is something that wasn’t possible 10 years ago,”

      True, but remember, telecommuting is something transit agencies will vigorously oppose. After all, it means they have less ridership and less revenue. You can’t tell me that transit unions would like to see that trend long term. That sends the signal to taxpayers, bureaucrats and politicians that there is less need for public transit if ridership and revenues are declining. You can bet subsidies and grants will dwindle. That’s one of those awful catch-22’s whereby what should actually be good from a policy-perspective, will be vigorously opposed by a group that it adversely affects. Tough problem.

  • Seth says:

    “But how do you make that apply to transit systems? Do we have to start time of day pricing?”

    The Metro here in DC already does that, the price is cheaper for the middle of the day and weekends. I think it is also one of the only systems that charge based on distance so intercity travel is cheaper but using it from out of the city to enter is charged more (would help cover the cost of building longer rail lines out there). Parking at stations is also free on weekends but charged for work days.

    Like restruants, transit could make use of membership benefits, coupons, and discounts for buying reservations ahead of time.

    But unlike private roads there is still not enough incentive to get things done quickly, when you are making losses on everyone you treat them different then when you are making profit on everyone.

  • Rose says:

    @ private toll roads comment

    won’t charging for big roads just cause more traffic on the free/smaller, neighbourhood streets? which in turn with cause disruption in communities, lower safety, and increase noise and pollution? not to mention also causing traffic speeds everywhere to increase by putting less cars on big roads and adding more cars who are in a hurry onto smaller roads?

  • Seth says:

    Cars in a hurry would want to pay a toll. Less cars on big roads doesn’t mean less people get to the destination, the incentive is to have the right amount to keep speed moving with as many cars as possible. The problem is too many cars right now.

    It would be smart for neighbourhoods to be designed to calm traffic (like the previous engineer blog post) and most are designed to not even be possible to be used as bypass roads. Most cities you can’t get to with neighbourhoods.

    It sounds radical but expensive roads with maintenance that bankrupt towns and city are overused, price is the best way to reveal the reality of supply (which changes by time of day).

  • Rose says:

    But charging for using roads may decrease the amount of cars on that road, but like you said, it won’t mean less people get to the destination. So how will they get there? … on a different road. If you take away the option of everyone using a big road, this will result in increased usage of smaller, neighbourhoody roads.

    Spreading out work start and finish hours, or making work days flexible, is much more likely to free up traffic backups, since people with a choice to drive to work during a lower trafficked time, will most likely pick that. Also, if people have a more flexible work schedule they can work around their life, rather than race from their work to maybe get to their life on time…

  • matthias says:

    The point is not to move car but to move people. Even in a traffic jams most seats in the cars are empty. If cars would be filled to their capacity most of the traffic problems wouldn’t exist.
    Singapore uses Electronic Road Pricing (ERP). There are ERP gates and a certain amount of money is booked from a prepaid card. The charge depends on the time of the day. What is interesting that a bus costs only twice as much as a car. But a bus carries much more passengers. So the ERP cost can be mitigated by filling the cars to capacity or by using busses. Of course if you want the luxury of traveling alone in your own car you pay accordingly.

    • Steven Dale says:

      @ matthias,

      “Even in a traffic jams most seats in the cars are empty. If cars would be filled to their capacity most of the traffic problems wouldn’t exist.”

      That’s precisely the point. We do not have a transit supply problem. We have a problem with how we use that supply.

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