People Not Vehicles
It seems that the goal of the Maryland State Highway Administration “is to get the most vehicles through the area in the most predictable way possible.” You often see transportation departments using metrics of this sort to evaluate different ideas. And it sounds at first glance a bit like common sense. But as Dave Alpert points out a small change in wording can make a big difference:
Even pedestrians aside, the goal should be to get the most people through the area, not the most vehicles. It’s an important distinction, since one bus carries as many people as a whole lane of cars.
Indeed. If you take a big, heavily trafficked urban thoroughfare — say a boulevard with three lanes in each direction that features a somewhat frequent, fairly popular bus line — and change it to two lanes of traffic in each direction, you’ll reduce the number of vehicles but possibly increase the number of people. The dedicates bus lane will speed the buses up. And since the buses now move faster, the exact same number of buses and bus drivers will be able to service the route on a more frequent schedule, since they’ll reach the turnaround points quicker. This would make the bus service into a more attractive option and if more people take the new, faster bus the increased fare revenue could support a further increase in the number of buses and drivers serving the route.
That all would, in turn, somewhat reduce the number of cars driving the route as some people switch away from the now-less-desirable driving option and onto the now-more-desirable bus option. That reduction in car volume would, in turn, somewhat counteract the increased congestion associated with the decrease in the number of lanes. A new equilibrium would eventually be reached. To estimate whether the new equilibrium would move people faster or slower than the old equilibrium would be a bit complicated and depend on various factors, estimates, etc. But if you’re considering making the switch, that would be the right thing to consider — the impact on the volume of people, not the impact on the volume of vehicles.
Beyond that, a transportation agency should probably take a somewhat broader view of its mandate and also think about things like the impact on the environment and economic development. But, at a minimum, when looking at transportation qua transportation you should be looking at the transportation of individuals rather than the transportation of conveyances. The essence of traffic congestion is that certain kinds of space are at a premium, so ignoring the fact that different modes of move people involving taking up more or less space means you’re missing a big piece of the puzzle.
63 Responses to “People Not Vehicles”
Register
RSSLogin
Topic Cloud
ArchivesBlog RollAbout Matt YglesiasContact Me
Donate
November 10th, 2008 at 4:16 pm
To nitpick a little, what about trucks? Roads are also used for commerce. I think you want to measure some kind of throughput of utility and it is a mistake to limit it to people.
I’m not sure your whole premise is right for that matter. If you’re designing a highway, you still need to optimize its vehicle capacity (within constraints) whether or not the same utility can be achieved with lower capacity. It would be like asking Intel and AMD to analyze whether their customers should be implementing more effective algorithms so they could use slower CPUs, or asking Cisco to study if people are really benefiting from all the video downloads in a significant way and might not be better off reading text transcripts.
November 10th, 2008 at 4:20 pm
I’d say an even better metric would be number of people transported per unit time per unit of carbon emissions created.
November 10th, 2008 at 4:23 pm
Sky Hook. No brainer.
November 10th, 2008 at 4:23 pm
On second thought, I agree that measuring vehicle throughput as such is not very useful, mainly because it is possible to have dedicated lanes for different kinds of vehicles. But given the way highways are currently regulated, this level of control is not used nearly as much as it could be.
I also concede that my attempt at an analogy is pretty flawed. Public agencies are not the same as private corporations. At the same time, simply establishing bus lanes by fiat is not necessarily going to get people on those buses and optimize throughput. I think that vehicle throughput may just be a better metric (and easier to measure) for highways as they currently exist.
November 10th, 2008 at 4:32 pm
Umm, Intel does spend time helping the customers make more efficient algorithms. They produce compilers, profilers, sample code, and such. Really. And since speed equals power consumption to some degree, getting better performance per watt used means battery life could be better, which customers really like too.
November 10th, 2008 at 4:32 pm
You will never get people on those buses until the current riders start bathing and using deodorant!
November 10th, 2008 at 4:53 pm
Riding the bus still sucks.
November 10th, 2008 at 4:54 pm
MobiusKlein: Granting that there are things that chip makers do that go beyond merely increasing the speed of hardware, the bottom line is that processors are still advertised using increasingly less useful metrics such as the clock rate. Even benchmarks that will give you a better comparison are not running better algorithms. If, e.g., someone has written tons of linear searches on long lists into their code, the CPU won’t figure it out, nor will the optimizing compiler most likely.
I also dislike my own analogy, so I’m not going to defend it with much energy. If I have a point, it’s that it might make perfect sense to optimize vehicle throughput within physical constraints (buildings that cannot be moved, budgetary considerations) and leave it to another agency to determine how best to allocate the vehicle throughput whether it is among private cars or public transportation. There is an advantage to considering both questions simultaneously, but it’s not clear how much of an advantage it gives you.
Conversely, I am not sure that highway planning really does maximize vehicle throughput (anyway here in CA), regardless of claims. I can think of a recently completed interchange that includes a separate ramp with a left entrance into the carpool lane. That ramp only makes sense in the context of preserving the continuity of a carpool lane between freeways, not maximizing overall vehicle throughput treating vehicles as identical. Most likely there are significantly fewer vehicles (and people) in the carpool lane when it is active. At times when it merely serves as another lane, it is doubtful that having a separate ramp increases throughput (and if it does, that’s coincidental).
November 10th, 2008 at 4:55 pm
ixermay, people on buses might not smell so bad if they weren’t stressed by wondering where the bus was, running after the last bus for an hour or the rest of the day and sitting stalled in traffic with morons in cars like you.
living in the fenway neighborhood of boston for 20 years, i am all too familiar with the pressures on city neighborhoods because of automobile commuters. the “highest and best use” of property becomes parking lots. if you increase capacity, you increase volume.
decrease capacity and run up costs for cars first (increase taxes on commuter parking). when it finally becomes expensive enough, commuters will start taking public transportation. once they have to deal with crappy buses and too few routes/options, it will improve, and fast (relatively speaking, of course).
November 10th, 2008 at 4:55 pm
Let me give a very specific example of how the roads are managed to maximize vehicle throughput rather than person throughput. This is the timing of traffic lights at points where buses exit Metro stations. (Think of the exits from Glenmont Metro onto Georgia Ave., from Wheaton onto Veirs Mill Road, the intersection of Church St. and Hungerford Drive at Rockville Metro, and the two intersections where buses leaving Bethesda Metro turn left onto either Old Georgetown Road or Woodmont Ave.)
Traffic lights at these intersections are on Montgomery County’s 100-second cycle, with a very short green for the buses leaving the Metro stations. Thus a bus waits almost 50 seconds on average before passing through the intersection. This timing maximizes convenience to automobile drivers (since the adjoining lights are on the same cycle, and the lights are timed sequentially). Most of these intersections could easily be converted to 50-second cycles without causing congestion. This would cause at most 20% of car drivers to be delayed approximately 15 seconds – an average delay of 3 seconds – but would reduce the average delay for bus passengers by almost 25 seconds.
The intersection at Rockville is a case somewhat different from the others. Here there is real congestion. Due to the light timing, I have not infrequently seen buses wait on Church Street during the evening rush hour two or three light cycles – three light cycles are 5 minutes – but I have not noticed multicycle backups on Hungerford Drive at this intersection.
November 10th, 2008 at 5:02 pm
Do you actually decrease the gasoline used (and Co2 emitted) by this method … probably not. By slowing down all the other cars, causing them to stop more and whatnot you are increasing the fuel they must use, and actually wind up hurting the environment.
November 10th, 2008 at 5:05 pm
Karen Marie, there is no such person as “ixnermay.” Ixnermay is a parody deployed by various individuals in the hope of preemptively deterring our #1 resident annoyance. So far it hasn’t worked, so you will no doubt be meeting him shortly if you stick around.
November 10th, 2008 at 5:08 pm
The point is that waiting time for vehicles is being minimized, not waiting time for people.
CO2 emissions from stopping and starting are not a consideration here – if you want to manage the traffic controls to cut CO2 emissions, the way to do it is to reduce speed limits to 40 mph everywhere, not to make bus passengers sit and watch drivers fly by.
November 10th, 2008 at 5:17 pm
I dunno about Maryland, but I’ve tried to think of a thoroughfare in the city of Washington that meets these criteria, and I can’t think of one, largely because there are hardly any bus lines with frequent service.
November 10th, 2008 at 5:34 pm
JimboSlice Says: November 10th, 2008 at 5:02 pm
You don’t just slow down the cars, you reduce the number … speeding up buses relative to cars shifts passengers from cars to buses. The only question, of course, is how many.
… (mind you, enough PHEV’s, and the stop and start driving and idling is not the same energy efficiency problem) …
It is likely to be more effective if part of the mix are quality express buses … especially if they can act to connect a useful origin to one or more dedicated transport corridors. If the local buses have bays to enter for some of their higher demand stops for debarking/embarking passengers, the express buses can pass the locals when the locals are stopped.
November 10th, 2008 at 6:12 pm
Matthew,
If you take a big, heavily trafficked urban thoroughfare — say a boulevard with three lanes in each direction that features a somewhat frequent, fairly popular bus line — and change it to two lanes of traffic in each direction, you’ll reduce the number of vehicles but possibly increase the number of people.
Yes, possibly you will. But possibly you won’t. Unless you can entice enough drivers to leave their cars at home and use the bus instead, you may end up reducing the number of people.
Of course, even if you could increase the efficiency of the thoroughfare as measured by passenger-miles of transportation along the thoroughfare per unit of time, that doesn’t mean the benefits of doing so would outweigh the costs.
November 10th, 2008 at 6:17 pm
Karen Marie, there is no such person as “ixnermay.” Ixnermay is a parody deployed by various individuals
Karen Marie, actually, I think it’s a parody deployed by just one individual, who has a serious case of obsessive-compulsive disorder.
November 10th, 2008 at 6:50 pm
Actually it just creates a traffic jam.
This isn’t a new idea. They’re called HOV lanes, and they’ve been a spectacular failure in social engineering of transportation.
I’d much rather have a train.
November 10th, 2008 at 7:16 pm
“It’s an important distinction, since one bus carries as many people as a whole lane of cars.”
Well, no. A bus CAN hold a lot of people. But that’s not always the case. Sure, during rush hour, there are lots of people on them. But during off hours there are not. Ever ridden a bus in Pittsburgh at 3 pm? Tumbleweeds. But of course, the buses HAVE TO RUN during off peak hours, because if they don’t they are even more inconvenient for people who ride them. Same is true for late-night routes.
Yes, you can reduce the number of runs. But that increases wait times and makes people less likely to use them.
I understand that it helps your policy proposals to assume that every bus is completely full. But it’s simply not the case. I could just as easily assume that every bus has one person on it, in which case I could write:
“It’s an important distinction, since one mo-ped carries as many people as a bus.”
Which is true. Sometimes. So why base decisions on either assumption?
November 10th, 2008 at 7:28 pm
The Mixner parodists are many. We all despise you.
The sad ‘no, you are’ responses, of course, are all just sad little Mixner
November 10th, 2008 at 7:31 pm
The Mixner parodists are many…
…multiple personalities of the same demented individual.
Get help, and soon.
November 10th, 2008 at 7:48 pm
Sam, I don’t believe that the wonks around make bold assumptions like 100% passengers to buses – leave that to us blog pundits.
Aiming to near 100% capacity during peak hours is OK because that’s when traffic is the worst anyway. When capacity is most restricted, that’s when mass transit is most effective.
And mind that achieving 100% capacity over an entire run is impossible, since some folks will need to get on after the first stop, and want to get off before the last one. But you knew that.
November 10th, 2008 at 7:54 pm
“Well, no. A bus CAN hold a lot of people. But that’s not always the case. Sure, during rush hour, there are lots of people on them. But during off hours there are not. Ever ridden a bus in Pittsburgh at 3 pm? Tumbleweeds. But of course, the buses HAVE TO RUN during off peak hours, because if they don’t they are even more inconvenient for people who ride them. Same is true for late-night routes.
Yes, you can reduce the number of runs. But that increases wait times and makes people less likely to use them.”
Smaller buses for off peak hours and lesser traveled routes!!!
November 10th, 2008 at 8:14 pm
Smaller buses for off peak hours and lesser traveled routes!!!
The former would mean two or more parallel sets of buses for a route, each of which would be idle while the other was being used. More buses to buy, more buses to maintain, more buses to park, more buses to get between the depot and the endpoints of the route. Those additional costs may exceed the fuel savings from higher load factors.
There is also an issue of mobility that limits the extent to which transit agencies can use smaller vehicles. Transit buses generally need to be large enough to allow for rapid entry and exit, easy access to seating, and special seating areas for disabled riders.
November 10th, 2008 at 8:37 pm
And mind that achieving 100% capacity over an entire run is impossible, since some folks will need to get on after the first stop, and want to get off before the last one. But you knew that.
Transit buses will rarely come close to running at 100% of capacity even during peak periods. The bus size and service frequency needs to be sufficient to accommodate demand at the busiest points along the route. Otherwise, you’re going to leave passengers standing at the bus stop at those points because there’s no room for them on the bus. But if your buses are big enough and run often enough to prevent people from having to wait for two or three buses at the busiest points on the route before they can get a seat (or get on at all), you’re probably going to have lots of empty seats at other points on the route where there is much less demand.
November 10th, 2008 at 8:50 pm
Mixner, I’m glad to learn that you never drive without three passengers in the rear seat.
November 10th, 2008 at 8:56 pm
tt, where did Mixner say that?
November 10th, 2008 at 9:06 pm
“Sam, I don’t believe that the wonks around make bold assumptions like 100% passengers to buses – leave that to us blog pundits.”
I don’t know about “100 percent,” but they do (and did) make a bold assumption like this:
“It’s an important distinction, since one bus carries as many people as a whole lane of cars.”
It’s 9 pm in Pittsburgh. I can see a bus stop outside my window. And I can tell that when the bus stops there, I can count the people in it. And they would fit in my Nissan Sentra. It will be like that until 6 am tomorrow.
So for a very good protion of the day, that bus does not, in fact, carry as many people as a whole lane of cars. It could if it was full. But it’s not full. It’s empty.
It just stopped again. One guy on it. Not, in fact, as many people as one would see in a whole lane of cars.
November 10th, 2008 at 10:25 pm
It’s 9 pm in Pittsburgh. I can see a bus stop outside my window. And I can tell that when the bus stops there, I can count the people in it. And they would fit in my Nissan Sentra. It will be like that until 6 am tomorrow.
So for a very good protion of the day, that bus does not, in fact, carry as many people Andas a whole lane of cars. It could if it was full. But it’s not full. It’s empty.
Sam, I’m really not clear on what point you’re trying to make here. People don’t travel much at night, so roads aren’t congested and buses aren’t full. We’re all agreed on that.
So…?
November 10th, 2008 at 10:36 pm
DMonteith,
Sam, I’m really not clear on what point you’re trying to make here.
He’s pointing out that in practise buses are very much less efficient than Matt suggested because they are so often almost empty.
November 10th, 2008 at 10:51 pm
L. Ron-
What does that have to do with anything…? The post is just saying that the goal of traffic engineering should be about moving people, not merely moving vehicles. But obviously at night, when roads and buses are sparsely used, there’s very little traffic engineering to be done.
It’s only during peak hours that we need to think about how to fit more people on the roads…
November 10th, 2008 at 11:37 pm
We are legion, Mixie. You are lonely.
November 10th, 2008 at 11:46 pm
We are legion, Mixie.
I know. Just how many deranged personalities do you have rattling around inside that head of yours, ixy?
November 10th, 2008 at 11:51 pm
Silly Mixner No-Friends. Every time he does his dumb-ass dance, someone new joins the Mixner Should Shut The Fuck Up Society.
November 10th, 2008 at 11:54 pm
I had sworn off bitching about Matt’s weird writing tics, but this one really set me off:
1. There’s that “qua” again! The word you’re looking for is “as”.
2. Is there any difference whatsoever between “looking at transportation as transportation” and just “looking at transportation”? Are there a whole lot of other ways to look at transportation?
I get that what he’s trying to point out is that there are other considerations beyond the sheer number of people and/or vehicles moved per hour, but really. The sentence from which I clipped the quote above uses the word “transportation” no fewer then four times. And it would mean exactly the same thing if you took out the “qua transportation” part. So why is it there?
I also get that this is a blog post, and not a peer-reviewed paper, so perhaps I shouldn’t be expecting perfection… but I’m willing to bet that I’ve spent more time proofreading this response to the blog post than MY spent proofreading the original post… and no one’s even going to READ this response.
The thing is that I really enjoy reading this blog, because Matthew has some really smart things to say about public policy. But the way he says them drives me to distraction. I can’t help but think that someone who writes for a living ought to do a better job of it. But the final thing I get is that I’m wasting my breath, because no one, least of all Matthew, particularly cares whether I approve of the writing style around here. And that’s fine too – I needed to vent about it, but now I’ll go back to biting my tongue.
November 11th, 2008 at 1:15 am
Matt, did you even read the article you linked? You took the quote completely out of context. Georgia Ave at Spring St moves into the downtown Silver Spring area, where street parking is allowed in non-rush periods to serve the local businesses. During the morning rush, there’s no on-street parking, so that all lanes can carry traffic (including a large number of buses heading to the Silver Spring metro). But during non-rush, when the right lane south of Spring is blocked by parkers, some drivers approaching the light use the right lane to jump the line of traffic and then cut in. In the article, a driver complains about this, and says, why not make the right lane a turn lane so people can’t jump the line? The official says, that won’t work because we keep the lane open for through traffic during rush hour. That’s through traffic for cars and buses. So what on earth are you talking about?
November 11th, 2008 at 2:24 am
It’s funny how this should be obvious but isn’t. The important thing is not how many vehicles throughput, but how many people, as well the most energy efficiently, or at least where the true costs are equitably distributed (i.e. you drive a Hummer or SUV, you pay substantially more for the inefficiency unless you’re car pooling, solo drivers in smaller cars should also be paying more).
The architecture stuff we can do right away, in terms of more people, while equitably distributing efficiency cost, which can only be done with higher gas taxes or more carpool and/or toll roads, is not something we can likely accomplish in the short-term with the political realities of our situation (unfortunately, because it is something we have to do unless oil prices do it themselves).
Ultimately, at some point we’re going to have to accept that we can’t subsidize energy and transportation inefficiency for poor and lower middle-class people anymore, i.e. it shouldn’t be a goal for everyone to be driving themselves to work or wherever they have to go every day and/or every trip, unless you can pay the premium to do that.
Otherwise, get on public transit with people like me. I haven’t driven a car since 2002, and it’s really not that big a deal, certainly not an affront on anyone’s dignity, especially with the savings from insurance and all that, and if you need a vehicle for a special situation, then you can rent, share or borrow one (or obviously own your car but just not drive it every time you need to leave the house).
Obviously, a focus on urban and people-friendly development would need to be concomitant with this change of societal thinking, over time, since many suburban areas are not friendly to other-than-automobile travel.
November 11th, 2008 at 2:49 am
Bus Rapid Transit:
http://www.streetfilms.org/archives/bus-rapid-transit-bogota/?autostart=true
http://www.streetfilms.org/archives/mobilien/
November 11th, 2008 at 9:47 am
thanks for the heads’ up, folks.
there are a lot of internet traditions with which i am not familiar.
November 11th, 2008 at 11:00 am
# Mixner Says, on November 10th, 2008 at 8:14 pm
No, since the frequency of the less traveled routes will be lower off-peak, providing some of the smaller buses for maintaining the frequency of the backbone of the route matrix, and the small buses will be in heavy demand Dial a Ride during peak commuting, which fleet will be available to complete the fleet of smaller buses for the high frequency backbone, it simply means parking the big buses during the off-peak.
We have bus systems that evolved in the 1970’s to turn of the century environment of heavy subsidy of car transport and ultra-cheap fuel. Bus systems designed for a different economic environment could well look to devoting more up front capital spending to achieve lower operating costs.
November 11th, 2008 at 11:35 am
No, since the frequency of the less traveled routes will be lower off-peak, providing some of the smaller buses for maintaining the frequency of the backbone of the route matrix,
Incomprehensible.
and the small buses will be in heavy demand Dial a Ride during peak commuting,
Huh? Why would “the small buses will be in heavy demand Dial a Ride during peak commuting?” Where’s your evidence? And how large are these “small” buses going to be? Dial-a-ride services generally use van-size vehicles, which are not suitable for regular transit use because of the mobility and demand-variation issues I described earlier.
November 11th, 2008 at 12:03 pm
Evidence that Dial a Ride is more heavily used during peak commuting hours, or evidence that small buses are used for Dial a Ride more often than big buses?
That’s odd … anyone as well-versed in transit issues as you ought to be able to read that without any difficulty at all.
November 11th, 2008 at 12:12 pm
Evidence that Dial a Ride is more heavily used during peak commuting hours, or evidence that small buses are used for Dial a Ride more often than big buses?
Evidence that “the small buses will be in heavy demand Dial a Ride during peak commuting.”
Again, how big would these “small” buses be? Why would transit agencies use them instead of their existing dial-a-ride fleets?
November 11th, 2008 at 2:07 pm
Oddly, I agree with Mixner about the ‘Incomprehensible’ paragraph. It’s a massive run-on sentence. Try rereading it then rewriting it.
November 11th, 2008 at 3:15 pm
Well, MobiusKlein, its quite true that its a run-on sentence. And “it” is a reference back to the beginning, which is not appropriate for a pronoun. Lessee:
No, that is not correct. The frequency of the less traveled routes will be lower off-peak, providing some of the smaller buses for maintaining the frequency of the backbone of the route matrix. The small buses will be in heavy demand Dial a Ride during peak commuting, so many of them will be available to complete the fleet of smaller buses for the high frequency backbone. Therefore, “Smaller buses for off peak hours and lesser traveled routes!!!”, means parking the big buses during the off-peak.
And you might well ask what “maintaining the frequency of the backbone of the route matrix” means, but Mixner, being an expert and all, certainly would not have to.
November 16th, 2008 at 1:11 am
I thought it was good. nice comment
March 11th, 2009 at 4:45 am
If you have to do it, you might as well do it right
March 12th, 2009 at 11:38 pm
It is the coolest site,keep so!
March 17th, 2009 at 2:30 am
I bookmarked this site. Thank you for good job!
tramadol
March 22nd, 2009 at 6:16 am
tramadol
Excellent site. It was pleasant to me.
March 22nd, 2009 at 10:29 am
buy viagra online
Incredible site!
April 2nd, 2009 at 5:21 am
I want to say – thank you for this!
buy cheap viagra
April 3rd, 2009 at 4:14 am
If you have to do it, you might as well do it right
cheap brand pfizer viagra
April 8th, 2009 at 8:01 pm
The quality of the info is what keeps me on this site, thanks!
April 9th, 2009 at 6:12 am
Excellent site, It was pleasant to me. viagra