« los angeles: rail has "forced ridership down"? | Main | if on-time performance is 96%, why am I always late? »

TrackBack

TrackBack URL for this entry:
http://www.typepad.com/services/trackback/6a00d83454714d69e2013485afc0b8970c

Listed below are links to weblogs that reference what does transit do about traffic congestion?:

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

mikef0234

You could possibly amend the pricing of road space to include the pricing of parking, especially where the parking supply is limited. Calgary is an example where the high price of parking and its limited supply play a similar role to road pricing.

The social justice and sustainable points are benefits of transit generally, and have less to do with congestion than the others. They could be included under the economic activity point.

Alon Levy

I would add two things:

1. Transit is like a road widening, in that it increases capacity, which immediately fills up with more cars. Thus, you won't see a reduction in congestion after a rail line (or new highway) opens, but if there is a temporary disruption to the line, for example a transit strike (or a bridge collapse), a traffic jam will ensue. This was actually studied and quantified at a transit strike in Los Angeles.

2. At high levels of transit investment, the amount of road congestion varies so that driving and taking transit have approximately the same travel time. This tends to reduce traffic, at least when there's a rapid transit alternative. It's not visible in the US Sunbelt, but in more transit-oriented regions, there's a fair amount of congestion saved by the existence of rapid transit. Even in Atlanta, transit reduces congestion more than operational treatments like signal optimization. The Texas Transportation Institute has the data on this for US urban areas.

Cap'n Transit

As I've observed many times, for example in response to the Libin article you posted last December, it really is important to keep all the benefits of shifting people from cars to transit in your mind when making these arguments. They can be broken into six categories:

1. Access for all
2. Cleaner air and water
3. Health
4. Safety
5. Efficiency
6. Better society

More importantly, the benefits are cyclic, as you mention in your fourth point. Improving transit encourages people to shift from cars to transit, which in turn provides more income for transit providers and more of a constituency for government-sponsored transit, bringing about more transit.

Your second point relates to Access for All, and your third and fifth points relate to Health and Safety. They all relate to Efficiency.

I happen to prefer my own formulation, but it doesn't really matter how you conceptualize it, as long as you're able to communicate the manifold benefits to your audience.

Cap'n Transit

Also, in the article you linked to, Weikel seems to be attributing the argument about a lack of congestion reduction to Tom Rubin.

Ben

I was going to echo the points made by Alon but he/she saved me the time :)

Also wanted to note, regarding your comment about how people pay for transit based on time and not money... it reminds me of something I heard a few years ago (before I lived in CA)... so I may botch this up... but there was a story about how on one of the SF-area bridges there is an HOV lane and that during peak traffic times the HOV lane would zip past all of the other lanes which were essentially going nowhere.

So some ingenious person(s) came up with the idea of standing on the side of the highway at the entrance to the bridge offering to be a second passenger for $20. Essentially this was a way for motorists to pay $20 and be able to ride across the bridge in the HOV lane, saving a substantial amount of time. On the other side, they would drop off the passenger who would do it again going back the other way. It said these people made hundreds of dollars a day doing this. Can't remember where I read it, though... it was at least 5 years ago.

I'm sure it's not allowed now, this being ultra-regulated California and all. If anyone knows what I'm talking about, please link!

Jarrett at HumanTransit.org

Cap'n.  Thanks for the correction; I will revise.

Ben.  The Bay Bridge's tolls, and long queues for single-occupant cars, have also spawned a "casual carpool" phenomenon.  There are several places in the East Bay where city commuters line up to get in the cars of complete strangers, so as to use the Bridge's HOV bypass lane, which also bypasses the toll. 

teme

Simple way to put it: Congestion is a problem because people can not get where they are going. Public transportation helps people get around, even if it doesn't reduce congestion.

Isaac Laquedem

Jarrett, you wrote: "Transit enables people who can't drive to participate in economic life." I think you've hit on a key point that transit advocates overlook. The question is not how to provide transit to the residences of the working poor; any decent transit network will provide access to a wide range of residential areas. The problem is getting the transit provider to provide efficient service to places of employment. When downtown was the center of employment, a radial network did this. Take Portland as an example that you're familiar with: in the 1970s most lines were radial and had one end downtown. You could live almost anywhere on the system and have a direct bus connection to downtown.
Starting in the 1950s with Tektronix locating in Beaverton, and then with the expansion of the industrial areas in Hillsboro that started in 1984, we've created large areas of employment that aren't well-connected to the transit network. People without cars can't get there to work. Put another way, the problem isn't that prospective employees are out of reach of the network, it's that the employers are out of reach, and thus people who don't own cars can't participate in economic life because they can't get to work.

Jarrett at HumanTransit.org

Isaac.  True, although employers must also take responsibility for their locational choices.  Some employment sites are so poorly located -- esp on cul-de-sacs -- that cost-effective service to them is simply impossible.  See the Portland suburban example embedded in this post:

http://www.humantransit.org/2010/02/portland-2010-service-cuts-announced.html

and this poist on the principle:

http://www.humantransit.org/2009/04/be-on-the-way.html

LA

Ben--its called "slugging" in DC, where it is a fairly common means of commuting. Check out www.slug-lines.com. There reportedly has been some crackdown on it recently by DC Police.

The Overhead Wire

Additional people that can't drive, Under 16s. In my suburb the ultimate freedom before the car was the bike. In many cities the ultimate freedom is transit. With seniors, disabled, disadvantaged and the young population, this is a significant number of Americans that have limited mobility.

EngineerScotty


Why would the police crack down on ad-hoc carpools? Sounds like rent-seeking behavior on the part of public officials, if true... never a good sign.

David Levinson

This is useful topic, but needs refinement.

1. You need to define congestion, you are conflating it with traffic (number of cars). Congestion is measured in a variety of ways, volume/capacity, congested time over freeflow time, % of time of the day in which speeds are below a threshold, etc.

2. Induced demand, while real, is not necessarily, nor generally 100%. Widening a road will produce a demand response, as would any lowering of price, but it will not necessarily lead to speeds being as low as they were before the expansion. There is evidence on this, and the range is wide (and context-specific), but the expanding roads cannot reduce congestion canard should be dropped. My work on this

Parthasarathi, Pavithra, David Levinson, and Ramachandra Karamalaputi (2003) Induced Demand: A Microscopic Perspective. Urban Studies Volume 40, Number 7 June 2003 pp. 1335-1353 http://nexus.umn.edu/Papers/InducedDemand.pdf

suggests elasticity of about .5% increase in traffic due to a 1% increase in capacity, so there *is* a congestion reduction effect.

3. Reduction of road capacity similarly does increase congestion (e.g. Vehicle Hours of Travel) (though may decrease number of cars or VKT). Our working paper on the effects of the I-35W Bridge reconstruction
http://nexus.umn.edu/Papers/I-35W-TRB2010-MeasuringWinnersLosers.pdf shows adding back the bridge reduced congestion, but contracting some of the traffic mitigation measures put in place after the collapse worsened it significantly.


4. Logically, a significant increase in transit capacity that is useful to travelers will attract some drivers out of cars. In North America, it is the significance part that is missing, and so it is generally immeasurably small on the roadway side.

I agree that selling transit on congestion reduction is misguided, it is like selling a road project on the extra space on the bus made available. The point of transit service is to serve transit users, not car drivers. If it can compete and attract some new riders, all the better for transit. If those new riders come from car drivers, and thus result in reduced congestion, all is good, but that is largely gravy.

eric o

"Transit enables people who can't drive to participate in economic life." With respect to the poor in particular I'm curious exactly how that amenity relates (indirectly) to reduced congestion. Intrigued. (Invariably, access to economic and educational opportunities eventually lead folks escaping poverty to purchase and add more vehicles to the road, won't it?)

But I know that in my city, poor people find ways to acquire automobiles anyway. They simply have no choice in sprawl. But this is at a high cost to them since their only option is to simply purchase less reliable autos. Transit often gives them the option to leave these unreliable autos parked to save on gas and repairs. It increases, their net economic power, and potentially helps them escape the cycle of poverty since it returns spending power that would otherwise go to auto maintenance.

Let me posit another way: The support base of your service/industrial sector economy is indeed filled by low-income individuals. Those are jobs that will be filled regardless in healthy economies. They will induce the same transportation demand. But by allowing those who can't drive access to these jobs, transit does reduce congestion in net terms. A transit rider going to work, will take a vehicle off the road.

These are some subtle and very worthy points above Jarrett!

Brent

Anthony Downs discusses this issue in Still Stuck in Traffic. He outlines a phenomenon he calls "triple convergence", in which new capacity (or, in this case, capacity created by shifting drivers off the road and onto transit) is filled up by motorists that previously had chosen to drive on other roads, drive at other times, or use other modes because of congestion. And, in the longer term, any remaining capacity and travel time benefit encourages more development on the fringe.

Toronto achieved significant downtown employment growth without increasing road capacity after the 1960s, thanks first to increased subway ridership and later due to increased commuter rail ridership. Congestion is still bad on the roads and expressways into downtown, even with transit expansion, but (as you say) the expansion of transit has permitted the downtown to grow beyond what the road network would have supported.

Over the last decade or so, this concept has been extended to pedestrian trips -- significant residential development on brownfield sites has enabled a lot more people to commute downtown on foot and has impacted the modal split at a statistically significant level. However this increased downtown residential population has also resulted in the development of reverse peak congestion on the downtown expressways, from new downtown residents commuting to suburban jobs that are more poorly served by transit.

Louis Haywood

A common straw-man argument arises when a single corridor service comes on-line, and then is judged by traffic reduction across the entire region. Transit often is not even attempting to serve the entire region. Two suggestions:

1) Benefits should be based on corridor statistics, i.e. a reduction of congestion, or simply the increase in transit modal share, of that particular corridor. Transit modal share = transit-using commuters/ total commuters with origins and destinations actually served by the rapid transit system.

2) If a person lives in an area impossible to be served by cost-efficient transit, or at a workplace that transit cannot efficiently served, this should not count against the transit provider.

Rob Fellows

Jarrett, good article, but a couple of nitpicks:

Widening roadways *can* reduce congestion as long as there are bottlenecks feeding the segment that's widened. You don't need to suppress demand, you just need to suppress the number of people that can arrive at that spot.

Reducing capacity has not been shown necessarily to reduce congestion, though it doesn't always make it worse as some people always expect. In the case of the Embarcadero, I spoke with a San Francisco traffic engineer a few years back (I don't have a reference for you unfortunately) who sent me a before and after study of traffic volumes on city streets - and all of the "before" trips were accounted for in increased volumes on parallel streets. The lesson I took away was that sometimes you have plenty of capacity to absorb the increase on the parallel streets, not that the traffic always just goes away.

I don't think either of those points weaken your argument though. I think the purpose of transit is to extend the range of pedestrians, to make cities better for walking, and to allow concentrated destinations to exist. So focusing on transit's effect on drivers usually misses the mark.

Jon Morgan

The estimated share of Americans who can't or don't/won't drive is 30%. All the groups listed above as well as people who refuse or are afraid of driving. Not an insignificant number.

Jase

Hi Jarret

a few things

1. I really, really like the concert-goers analogy. I think it really speaks to people who might not have believed in pricing reducing congestion before. It's simple and evocative.

1.1 I'd like to see you add to your version of the analogy this: the concert goers give up a lot of something valuable to them (time), and yet the performers receive no benefit.
Making people pay with money not time means less loss to society

2. I think you shouldn't focus solely on the economic life of the community. Kids with no 'economic life' take transit to education, and people travel all over simply for pleasure.

Samuel Scheib

I recently had a post on this very subject, (http://www.tripplannermag.com/index.php/2010/07/transit-is-in-the-business-of-moving-people-not-relieving-congestion/) and the crux of my argument is that in the transit business we promise congestion relief at our perile. As you have noted congestion goes away primarily as a result of poor economies, but transit agencies constantly promise a new light rail or other transit project will make people's drive easier. It will not because congestion is a matter of perception. VMT we can reduce, but as long as there is delay people will perceive the presence of congestion and that cannot be fixed (with transit or road projects).

Jack Horner

Thoughts in no particular order:

1. Need to define 'congestion'.

2. Presence/absence of congestion is not a useful measure of transport system efficiency without more information. Total resource costs needed to satisfy transport needs is the better measure.

Ms A commutes 5km at 30kph on nasty congested roads: time 10 minutes. Mr B commutes 20km at 80kph on lovely motorway: time 15 minutes. Who is better off? A, clearly.

Urban consolidation should be expected to increase congestion, since the hoped for extra training/ bussing/ cycling/ walking is unlikely fully to make up for having less road space per person. Yet it may still be beneficial in terms of resource costs to satisfy transport needs if it brings people closer to the places they want to go, to an extent that outweighs the slower travel.

3. David Levinson: "Parthasarathi... suggests elasticity of about .5% increase in traffic due to a 1% increase in capacity, so there *is* a congestion reduction effect.

Short term? Long term? You would expect the long term elasticity to be greater as people adjust their habits (eg residential location choices) over time.

From change of behaviour by the folks originally present? Or allowing for car dependent growth fostered by the road spending?

In reality there's no point trying to distinguish these. 'Road dominated transport investment creates car-dependent cities' is an essential part of the equation.

Is there a large, growing, car-dependent city anywhere which claims that the last 30 years of max road spending have solved its congestion problems?

At this point favourite trope of the roads lobby is 'but think how much worse things would have been without all that road spending'. But the hypothetical 'today's car dependent city but without the last 30 years of road spending' is absurd - without the road spending it would now be a different sort of city. The alternative hypothetical 'the city as it would have been after 30 years of transit-oriented development', being at least possible, is of more interest in imagining a desired future.

David Levinson

@ Jack Horner. The paper has elasticity summaries for short and long term effects, and it of course increases over time, that was from a long-term (8 year) measurement on fwys.

All successful cities are congested on their roads, sidewalks, buses, and trains, demand is growing faster than capacity can serve. I am not advocating additional urban road spending, just that the claim that capacity does not reduce congestion be retracted. In theory, one could build your way out of congestion, it is just not worth doing because the costs outweigh the benefits overall, but it doesn't mean you can't build something that reduces congestion in selected places.

Steve S.

The Portland Oregon region has been pursuing these concepts for a long time.

Where in the Portland region is anything but a demonstration that it is a futile pursuit?

After being repeatedly and still lectured about rail transit spurring development and prefferable community all we get are major flops and millions more spent trying the same thing.

It's Ok to talk therories and the desire to achieve some better approach but at some point the talk gets pertty stale when it never comes to fruition.

Yet every time this point is raised the response is always more of the rhetoric about the concepts.
Perpetual talking about what the theories and intentions are is no substitute for effective implementation.
Neither is the endless presumptin that any and all alternatives to the planning class is the extreme opposite of good intetnions and planning.

Vin

David:

One minor quibble with your post - you seem to imply that transit users and car drivers are distinct groups. I think this is rather incorrect. I know many people, myself included, who regularly both use transit and drive. And it's not just the transit to work/drive to everything else split common in the suburbs of many major cities. Clearly, there are many, many people who almost exclusively use one or the other, but there is quite a bit of overlap, as well.

Kyle S.

Steve, you will need to define "flop." Part of the point Jarrett is making is that traditional expectations of success (reduced congestion) are not likely results of transit investment.

Michael M.

This is somewhat OT, but I don't think the "flop" Steve is talking about is about transit's effect on congestion, but transit's effect on development. I suspect he's referring to efforts like the "Round" in Beaverton, which was touted as a shining example of what transit-oriented development is supposed to produce, and has turned out to be something of a flop. There's a growing push-back (from the citizens, not the planners) against TIF and urban renewal schemes that starve districts of tax money for essential services to subsidize private development and public transit capital projects. That's not really the issue JW is discussing here, though.

taiwan

A friend was just telling me yesterday that in Taiwan cars will often try to pull in front of or tail ambulances to get a free ride through traffic.

Steve S.


By flop I mean the entirety of the concepts.

"emphasizing rail transit, mixed use, transit oriented development, centers and corridors concepts."

All tax subsidized and devouring in totality countless millions in perpetual pursuit of a theoretical community.

While in reality we have tremendous failure with developments, we have diminishing and and increasingly unhealthily bus transit system, unsustainable massive debt piling up, lack of added transit mode share and real world problems with the entire approach which are always ignored and even obscured with endless pronouncements that it is working well.

It's not.

Facts are facts and all the enamoring over a sustainable walking, biking, transit community is not the same as success.

Drum beating that any and all added road capacity worsens congestion is the kind of inaccurate yet wishful thinking that perpetuates failure.

It's a default position used to ignore failure and justify more of the same because anything else like adding road capacity would be even worse.

Well there's a lot of wide ranging options for policy changes between more of the same and adding large rod capacity.

It's not a choice of abandoning transit in exchange for a movement to add roads.

The high cost, slow and low capacity rail transit that the Portland region is pursuing must be stopped. Along with the many millions being spent trying to develop what the rail transit failed to spur.

Instead we have the head of TriMet saying our "rail transit has prompted $8 billion in development".

This level of distortion and public deceit will lead only to failure on an even grander scale.

Rodrigo Quijada

Excellent article. Great analogy with concerts.

I think the only error is the implied assumption that reducing congestion should be a goal. Or more precisely, that the measures we take to improve transportation in a city should be intended to reduce congestion. Stated in such a fashion, you're likely to conclude, as you did quite correctly, that transit does not help, but only through an indirect, less important way.

What we'd like to do in a city is to reduce TRAVEL TIMES. Reducing congestion is a way to do that, but in no way the only one. Over the decades, in places where car transportation has become dominant, people have got used to see travel times and congestion as the same thing, thus orienting their thinking and their solutions to reduce congestion. But this is essentially a confussion.

Public transportation is helpful because it can improve travel times, while not making (necessarily) any progress in congestion levels. Imagine a congested city where you go and build a subway. All those who shift to this underground mode will get *faster* to destination. And the speed they'll enjoy will be "sustainable" in the long run (it won't decay as time passes by). In the surface, although you may see some congestion relief after the subway starts operating, in the long run new cars will fill up again available capacity, and congestion will return to its previous level. So we can say the subway did not improve congestion. Yet, it improved travel times, which is what's really important.

So my suggestion would be: add "improving travel times" to your list of values provided by transit.

Paul K. McGregor

I agree with your points. I think within the transportation profession, we can agree that congestion is a sign of a healthy economy. But trying to convince the average citizen and politician of that is another challenge. I give credit to the mayor of Honolulu [who is about to resign to run for governor] who is trying to promote rail as an alternative to driving not as a means of reducing congestion. Anti-rail folks keep promoting a highway based solution which really doesn't solve congestion either.

Another discussion point that someone touched on earlier is the notion of providing people with choices. Although I no longer own a car and still spend 99% of my travel time on transit, I still am able to use a car for that 1% of the time I need one. Carsharing is another idea that has caught on in Europe but is a hard sell in the US. I have been fortunate enough to live in cities with carsharing and have used it when I needed to. Now the concept is being expanded to bikesharing with an extensive system just opening in Denver.

So expanding transportation choices like carsharing, bicyling, walking, etc. is another way to still provide added capacity to the transportation network.It's not just about expanding the highway network or building another rail line or adding another bike path. It's about developing a transportation network that can provide us with the mobility a region requires to support economical and sustainable development while at the same time preserving the environment and providing for a good quality of life for all.

Eric Doherty

There are situations where transit improvements reduce or eliminate traffic congestion. And these 'test tube' situations tell us something about the larger picture.

For example, the University of BC and connecting roads saw a significant and long lasting reduction in traffic congestion after introducing a universal transit pass for all students. Parking was already expensive at UBC, by student standards.

UBC is a test tube situation since it is on the end of a peninsula, so traffic is easy to study. You are just not going to normally see significant changes if you add one transit line in the middle of a complex urban region. You need to look at 'test tube' situations like peninsulas or areas with only one bridge.

Something might also be learned from areas where very large changes to transit have happened quickly. Has anything been documented from Bogota when the Transmillenio lines opened up?

On the other hand, traffic congestion is a useful phenomena. Transit does not have to be super fast if car travel is slow.

ws

If I am not mistaken, the highway movement in the 50s was also billed as a congestion reliever, among other things.

Possibly it did relieve absolute gridlock for surface streets, but really that congestion just moved towards the highways.

The whole road widening/extension is just a rinse and repeat scenario. Widen roads, develop senselessly along its periphery, and widen them again to relieve the congestion (and then develop even more).

Unfortunately, our entire economy has been hinged on that type of economic growth for the last 60 years.

We will never conquer the mystery of traffic congestion. That doesn't mean we shouldn't do things to alleviate congestion with a best practices model, but the way we do things needs to be flipped on its head.

VR

I disagree with Steve. I don't consider the Portland system to be a "flop". I have lived in many cities across the USA, and I find that Portland is much more livable and enjoyable for all people as a result of having good transit and dense and well planned communities.

But one thing that always frustrates me is when people compare a completely pervasive and built-out road system to a new or fledgling transit system, and then call transit a failure.

When we have thousands of roads that reach every corner of a metro area - and only 4 or 5 rail lines and 100 bus lines which reach maybe 50% of a metro area - of course you are going to be able to get somewhere in a car that you can't get on a bus or a train.

If we built out our bus and rail systems to the same level as we build out our road systems then the comparison would be valid.

People in Portland are criticizing the Portland Streetcar as a failure because it only goes a couple places and is not fast. Yet every time I use it the thing is full - presumably full of people who would either be driving, or not making the trip at all otherwise. That looks like a success to me.

Also, people have criticized the Streetcar in Portland as being just for tourists. Which may or may not be true, but so what? Because they are tourists they are not allowed to get around? Should we tell tourists not to come to the city? Don't tourists cars clog roads and emit pollution just like any others (maybe more since they are likely not sure of where they are going)?

In the end I feel that the success of a Transit system is about freedom and options. I should have the freedom and option to not own a car. Being forced to own a car is as un-American as being forced to ride a bus. I want the option of being able to walk, ride a bike, ride transit, or drive.

Alon Levy

Jack: in your example, it's not clear that A is better off than B. The presence of jammed roads is annoying by itself, and is to my knowledge reflected in traffic modeling. It's the road equivalent of a transfer penalty in transit.

Steve S.

VR

I don't think you know what the Portland "system" is, what I am criticizing or what you are advocating.

Portland's level of livability is not a product of our contemporary planner's flops.

And they are flops. They simply refuse to acknowledge them while insisting more of the same is needed.

Essentially all of Portland and the surrounding area's current livability has no connection to the costly experiments we've been forced to pay for and subjected to.

In fact the very Charbonneau development that was criticized for devouring farm land and led to Oregon's SB 100 and the central planning regime has been and is one of the most livable communities in the State. And it was entirely privately funded.

Yet a few miles away is the contrasting current government planned community that will soon devour $100 million in subsidies only to produce a glorified subdivision that is car oriented as any.

Our older Portland and vicinity neighborhoods are all better than the recent seas of asphalt, concrete and roofs which our Metro central planning has mandated.

The various subsidized experiments with infill have actually been a bad fit for many of these neighborhoods while costing countless millions .

Your frustration with transit criticism needs some clarifying treatment. The reason our transit system is fledgling is due to the misguided pursuit of rail transit at the expense of the greater transit system and use which would otherwise have bee possible.

Billions have been spent while bus service has been sacrificed and the mode share of transit use has not been increased.

Yet we're supposed to spend billions more?

Good transit in our region takes a healthy bus system. But TriMet is carving the bus system up and is making more commitments which will carve it up even more.

Yes there are thousands of roads that reach every corner of a metro area. Too bad we are not using modern buses and jitneys to provide better transit to all of our neighborhoods.

We are not building our bus system, that's the beef. Instead we are building $215 million per mile MAX rail when buses would be better, a WES commuter rail that was never a good idea, and a Green line MAX boxed in by a freeway and commercial development, MAX down the middle and obstructing blocking of well functioning Interstate avenue arterial that buses once ran well on. It goes on and on with bad decisions that cannot be well with hype.

The Portland Streetcar is municipal bling that is slow and costs a fortune to build and operate.

It may "look like a success" to you but it only successfully devours huge sums.

Portland is not a big tourist destination either.

The countless millions spent on this municipal bling would be better spent on bus service and community improvements.

If a transit system is about freedom and options and you want more people to have the option of being able to walk, ride a bike, ride transit, or drive then you should join the effort to stop MAX expansion. It's killing those choices.


Michael Wilson

Sorry VR Steve is right. I'll give you an example and by the way I lived in Portland for some 20 years.

North Portland was primarily black until a few years ago. And poor. North of that area just 5 miles away is the Rivergate Industrial Park, home to some 80 companies and job opportunities, but the bus service between the two areas is best described as poor. The focus in Portland is on downtown and on building light rail. And Trimet built the Westside Rail project which has been a disaster financially.

I have been away from there for a few months but I doubt that things have changed. And this is just one example of many I can come up with. I also wrote to politicians and testified at more than one hearing on the issue. Portland has an excellent Public Relations program. That much can be said about it.

jack horner

@ Alon Levy on the stress factor of traffic congestion: by 'nasty congested roads' I really meant 'slow travel on local roads' (by contrast with motorways). Nothing wrong with that providing the road system is predictable and adequately tweaked to allow smooth flow. The stress of congestion is mostly to do with not knowing whether you will be held up for 2 minutes or 20.

The basic point is that judging transport system efficiency must consider distance travelled as well as speed.

In car dependent post WW2 western Sydney on average people use cars much more, drive much further much faster on better roads, and spend slightly MORE of their day travelling, than people do in the more transit oriented pre war east.

CroMagnon

2. Reduction of road capacity. Ever since the demise of San Francisco's Embarcadero Freeway, it's been pretty clear that if you reduce road capacity for private vehicles, traffic will drop in response. ..."

I certainly agree that transit shouldn't be sold as a device to reduce congestion, only to keep a lid on it (unless you have a permanently flat economy.

However, I don't buy the second argument. It could be true, but not necessarily. The problem is that one could argue eliminating all traffic capacity with no significant damage. Removing traffic lanes to accommodate dedicated transit makes sense if the road is below capacity and the transit only space doesn't consume the remaining capacity or the transit transfers enough trips from the vehicles, or thirdly, there are parallel auto routes with sufficient capacity for traffic to be diverted effectively.

If reducing road capacity doesn't lead to increased traffic elsewhere, it could be the road trips were simply destroyed. Usually this is not a good thing, because the purpose of most road/transit systems is to increase productivity and economic output (it's probably good for the environment, though). Likewise, making car congestion worse to make transit seem better is counterproductive, esp. if the new transit service is slower than driving was before. Whatever else we can say about highways, they certainly increased productivity and economic output by allowing goods and services to be distributed and consumed at faster rates. Transit shouldn't reverse that. We can collapse our economies through cheaper means--it's not worth building slow transit that makes driving slower, too. Just close off half the roads and make everyone ride buses through auto fees instead.

"Transit-dependent cities are generally more sustainable than car-dependent cities."

Something is either sustainable or it's not! Frankly, the transit cities are simply heading into oblivion at a SLIGHTLY slower rate!

"Surface exclusive transit lanes (for buses, rail, and arguably two-wheelers and taxis) improve the performance of emergency services."

Maybe for bus, not for rail. No way. Not at least in the big project proposed near me for LRT. Intersecting streets get cutoff but 8" curbs for the ROW and all traffic. It's not worth it for the operation of the rail line. The disruptions would be constant--not worth it.

anonymouse

CroMagnon: you forgot externalities. For example, let's take a car trip to a big box store 10 miles away. That could have been replaced with a walking or biking or even car trip to a smaller store closer by, but the bix box store was chosen instead, presumably because it was cheaper. And you could argue that the extra cost of buying things in the smaller store is wasted money, and you'd be right. But removing that trip also removes all the externalities of that trip, which might well be more than the money saved by going to the big box store! These externalities include things like marginally increased congestion for all the other traffic on the road, increased air pollution, increased chance of collisions, and so on. Transit supporters tend to believe that driving is underpriced relative to the cost of these externalities, and that removing these trips (and the economic activity they represent) will actually be a net economic benefit to society. What's more economically efficient, saving $5 on a 100-pack of widgets, or one less child with asthma?

anonymouse

I forgot a key word in my previous comment: marginal. The key point is that at the margin, that is, when we speak about the least valuable car trip, which will be the one that will be the first to go if capacity is reduced, the externality costs of that car trip outweigh the economic benefits.

jack horner

@David Levinson on elasticity of demand for car travel with respect to amount of road space: Thanks, I agree. Further thoughts:

1. Transit supporters are apt to say 'traffic expands to fill the space available' (to talk down road spending), and 'transit helps reduce traffic congestion' (to talk up transit spending). But these statements are contradictory. [?]

2. See 'Braess paradox' eg on Wikipedia for demonstration that under certain conditions road expansion may make traffic slower even without any induced traffic/ mode shift. A question of interest is how often the rather artificial conditions occur in real life.

3. I tentatively conclude that either better transit or road expansion may reduce traffic congestion *other things being equal*. But in the real world other things are not likely to stay equal for long, and the more important question is 'How is the city's future development influenced by different transport policies?' To which the more important answer is, 'Road dominated transport policies create car-dependent cities' (in concert with complementary planning policies eg on urban density, location of activity centres etc.)

4. Need to unpack what we mean by 'road dominated transport policies'. I suppose I mean something like 'attempting, by building roads, to accommodate growing car use without worsening congestion'. Of course in greenfields development you have to build roads - the question is whether you plan them assuming that over 90% of all travel will be by car, and with the aim of making that easier. In established pre-car areas, the question is whether you should try to enlarge the historic road system in response to growing car use.

5. What forms people's views of 'acceptable' congestion? When I drive from A to B I don't expect to have a motorway from door to door - I accept that I will have to slow down to turn corners, climb hills, stop at traffic lights. So why do I become grumpy when I am forced to slow down by other motorists (beyond a certain point)? Why don't I just accept them as a geographical fact like the other things? Part of the answer may be that congestion makes travel time unpredictable, which is stressful, more than the other things.

CroMagnon

anonymouse,

Let me simply reinforce my contention that one could do the same thing, by simply making driving more expensive or otherwise more onerous and not providing any extra transit either.

It's possible this reduces negative benefits (externalities here)to a point where the value exceeds the costs. However, this approach certaintly doesn't increase actual wealth, it just means you'll spend less on certain things. Absolute wealth will still decrease and we'll become poorer and the country/world will recess.

Spudhead

Two points that haven't been made:

1) Transit allows an individual to make a more economically rational choice of transport mode. When transit exists an individual can choose to delay purchasing a car and still participate in economic life. Cars have a very high fixed cost component - delaying the purchase of a car makes sense to an individual. For example in Australia a typical 4 door sedan if purchased new is about $36000. Assuming you depreciate this capital component over 10 years that is a cost of $3600 a year, or $70 a week. To this you would need to add registration and insurance - registration is $624 a year (where I live in Melbourne) and a similar amount for insurance. So add another $23. You would then have maintenance cost on top of that. In total the cost of owning a car is about $100 a week. And I haven't even included operating costs such as fuel or parking.

If transit isn't present it acts as a cost to the individual as, in order to participate in most economic activities, they are required to purchase a vehicle. As an example, because I can catch transit to work my wife and I only need one car - saving us at least $100 a week. When purchasing our house we included these costs in our calculations and determined that we could afford a house to spend about an extra $90000 if we purchased a house in a suburb with reasonable transit. Once we pay off the mortgage if we simply put that $100 we save by not having 2 cars in a bank account with an interest rate of 3% over 30 years that will amount to $252,760.14!

2) Transit allows for the a reduction of the cost of externalities per journey made. The externalities include things such as carbon pollution, noise pollution and even traffic congestion. The key is that the even though the overall level of traffic congestion, carbon pollution due to vehicles and noise pollution may not change, the presence of transit allows more journeys to be undertaken, thus reducing the cost per journey.

anonymouse

CroMagnon: allow me to take my argument to an extreme just to highlight the point. Suppose person A wanted to drive to Walmart to save $5 on a box of widgets. Suppose this driving would have produced so much pollution that the increase in pollution level would cause one child to get asthma. The person saves $5 on widgets, but the child will end up spending, say, $10,000 in medical costs over their lifetime rather than on something else. Thus, not taking that trip would hypothetically have increased the sum total of wealth by $9995. Are these numbers realistic? I'm guessing they're not. The problem is that it's hard to accurately price the externalities of driving, and that's where economics ceases to be about math, and starts to be about psychology, often that of the economists themselves.

CroMagnon

I don't think that by not driving in your example that wealth is increased by $9995. I think one is simply eliminating a cost people can't afford anyway. Reducing driving, reduces costs. It doesn't increase the wealth--which is the benefit. Time savings increases wealth (faster transit, highways, the like) because more resources can be exploited at a higher rate. Therefore, an individual reaping the benefits of those exploits will have greater wealth at any given point in time. I see the point you are making, but I'm framing this in terms of absolute wealth and productivity. You're arguing that it's cheaper to live in a cleaner environment (which is a good thing). But in that environment, one is limited in his money making abilities by the costs of paying for more damage down the road.

Basically, I think the 'congestion is ok' argument boils down to limiting external costs in the future that we're not paying for now; but we'll be making less money, too--so we don't make the external costs worse.

Additionally, I'm convinced some LRT and streetcar systems make pollution worse. Increases in auto congestion on the streets they travel because of their own presence might exceed efficiencies derived from higher capacity vehicles and modest increases in ridership from auto.

anonymouse

CroMagnon: the kid not suffering asthma increases the wealth he produces during his lifetime. Perhaps I should have used an example where someone is killed? Then it's clear that the world loses the entire amount of wealth they would have produced. And there's always a non-zero probability of killing someone when you drive a car, so there's some non-zero expected value of wealth that you destroy by driving. In my example, I'm also looking just at the externalities of that one hypothetical smog-cloud-making car trip. Any future car trips would presumably give more kids asthma or cause more oil blowouts in the Gulf or whatever. BUT! This is all purely a thought experiment. What I'm saying is that it's mathematically possible for things to be the way I describe, and the difference between you and me are our estimates of the relative sizes of the externalities and benefits of automobility. I'm also claiming that these estimates differ in part because of who is doing the estimating and how far they are searching for externalities and/or benefits, and what their own subjective experience tells them the estimates of their sizes should be.

As for "making pollution worse", that's something that you'd have to look up by numbers and you might well be right, but one effect that I commonly see that makes such estimates deceptive is that people in cars look really large, making one overestimate how many there are, whereas people on foot, or in trains or buses look relatively small, making one underestimate how many there are relative to the number of people in cars.

ws

@Steve S.

I actually agree on a lot of your points (particularly with slow rail service, infill homes, etc.) but I feel much of your ire should be directed at the top-down planning of the highway-suburbia typology that destroys livability many times more than Metro ever has.

The "Portland way" was merely just trying to mitigate these effects with an antidote.

Why aren't you angry at the 1/4 acre lot ranch homes set upon dead end cul-de-sacs that consume tons of land, makes bus service crazy expensive, and halt walkability and basic transit access of any kind in its tracks?

Maybe you are angry at these things, but it sure doesn't sound like it. I am far from believing that Metro is not culpable in bad decisions, but I can at least direct the correct amount of anger at the right sources.

Alon Levy

CroMagnon: according to the Texas Transportation Institute, mass transit always saves congestion cost rather than increases it. In rail-heavy New York, it saves $7 billion a year; without it, New York would have had the highest per-driver congestion in the US, ahead of Los Angeles.

What you say about reaping natural resources isn't exactly true, because not all kinds of economic activities are equally polluting. For example, producing $1 million in software is nearly pollution-free, whereas producing $1 million in oil emits a fair amount of carbon dioxide, carbon monoxide, and other nasty gases. It's unmistakable on the national level: compare the GDP-per-CO2 ratios of Switzerland and Hong Kong to the ratios of the US and Canada.

Bossi

>>>(Widening roads is not one of these ways, because its benefit to traffic congestion is temporary unless new development in the road's catchment is completely and permanently banned.)<<<

Someone above may have already mentioned this, but this statement isn't entirely true -- residual demand may still fill in new capacity even without necessarily creating new demand.

CroMagnon

Alon, ALWAYS? Obviously, I'm not talking about NY, because I mentioned removing existing utilized space for transit, so NYC doesn't fit that bill at all.

IIRC, Switzerland is dependent on other natural resource producing countries to allow its economy to thrive. We can't all be like Switzerland by holding other people's money. Some need to be like Saudi Arabia and Canada. And I'd claim that designing software is fairly resource intensive, since keeping all those computers running with all the component metal parts that cause pollution when they're intentionally or unwittingly placed in landfills.

EngineerScotty

CroMagnon,

As a professional software developer, let me assure you that for many SW development tasks, the computing demands aren't any more difficult or onerous than other reasons one would have a desktop computer around. Large-scale collaborative development is aided by having powerful servers (and many developers LOVE having cool toys to work on); but much work can be done on a garden-variety PC. In terms of energy consumption, activities such as watching multimedia or playing high-end video games are more resource-intensive than editing source code, or running development tools--especially on modern systems where power consumption is scaled to the processor load.

SW development is no more resource intensive than any job in which information is manipulated or generated--clerical tasks, transit planning, blogging. :) And like many of these other positions, it can be done remotely, saving many trips into the office.

CroMagnon

^Sure. There's no question that's true. But most software is used to facilitate real, physical work someplace else. To get back to the main point of transportation, the basis of any economy must revolve around some actual work in the physics sense. Slower transportation reduces that relative to faster transportation (for better or worse)--that is the point.

Many transit projects are sold on the notion that it will increase the ability of the poor to reach more jobs by making home to work travel times short enough to be able to reach that job with the other demands in a 24 hour day. Making transportation slower can't accomplish that. Reducing roadway capacity can reduce the speed of connecting bus service to a new transit line, thereby potentially undoing the benefits of the new service.

Steve Munro

In linking to this article from my own site (based in Toronto), I commented:

Dense cities with good transit (or even cities with a good potential for better transit) don’t appear out of thin air. Once we build sprawl, then the benefits and effects of transit seen in the older, denser cities will not appear overnight even if we run the most intensive BRT, LRT or subway network through auto-oriented suburbs. Transit can make things better, but it will not reverse the damage and inevitable congestion of decades of bad planning.

alex

RE: "Years ago, politicians and transit agencies would sometimes say that a transit project would reduce congestion, though most are now smart enough not to make that claim"

Mayor Villaragoisa claims that rail reduces traffic congestion almost ever time he speaks on the subject. The Los Angeles Times also repeatedly claims rail reduces congestion in their editorials and in their articles. In fact, this was the first time I've seen them acknowledge that someone actually thinks it doesn't reduce congestion.

Andrew

Jarrett, I appreciate your holistic approach to enumerating transit's strengths. When people think about transit they often aren't looking at the big picture.

I'd dare venture to add: transit also enables people who can't drive (or otherwise get around) to participate in democracy. As far as I know, not every state enjoys a mail-in ballot system (as we were the first to do here in Oregon). Those with disabilities, or in economic hardship would not be able to put in their vote on important issues without convenient, timely public transport.

Alon Levy

CroMagnon: yes, always. The amount of congestion saved by mass transit is always positive. In many of the larger cities, even Atlanta, mass transit saves more congestion than operational treatments.

As for Switzerland versus Saudi Arabia, what you're still missing is that there can be different mixes of resources in an economy. Just like an economy can consume more oil and less steel, so can an economy consume more renewable and sustainable resources (for example, highly skilled labor) and less non-renewable ones.

So even at the point of consumption, different economies have different sustainability levels. Hong Kong and Switzerland really do consume lower-emission products per dollar than the US and Canada. It's not just outsourcing pollution to other countries.

CroMagnon

Alon, I'm talking about individual transit services, like LRT taking away traffic lanes--not whole systems. So I can't take the absolute claim that mass transit ALWAYS reduces congestion, seriously.

I believe you're missing my point about economies. Some economies can be like Switzerland, but most cannot. The others have to do real work which where the congestion/time savings issue is more significant.

M. Briganti

In Toronto's case, the opening of the Yonge and Bloor-Danforth subways significantly reduced congestion on the roads those subway routes travelled under almost overnight. I haven't seen any modern streetcar or light rail line do this.

Alon Levy

LRT very rarely gets fewer passengers than would fill a traffic lane.

And I'm not missing your point at all. More economies can be like Switzerland than you think; if externalities were priced properly, you'd see a shift in which the world would produce fewer goods creating a lot of pollution and more creating little pollution.

Kelly Clifton

I'd add one more to the list of "what transit does". Transit networks can add system redundancy and perhaps leading to a more stable or reliable transportation system overall. So for many road users who rarely or never take transit, it still provides an option for those occasions when the road network or vehicle fails. Again, not a reason on its own to justify the expense, but one more to pile on the list.

CroMagnon

Alon, I'm sorry, but that's not what I'm saying about LRT. I'm saying that the number of people who are likely to be transferred from a traffic lane using an auto to LRT is smaller than the capacity the LRT would reduce on that same road--in some cases.

If all externalities were properly priced, we'd all be broke and have little economic output. This may be necessary to save the Earth somehow, but I don't think it's going to lead us all to live like the Swiss. We'll have to agree to disagree on this, because it's not scientifically testable!

Alon Levy

Can you name a single case where auto-to-LRT ridership diversion was lower than a traffic lane capacity?

anonymouse

CroMagnon: I take it you're in the "we're screwed" camp, with the view that it's got to be either the environment or the economy. I'm a bit more optimistic and think that if externalities were properly priced, the economy, being as adaptable as it is, would find more efficient ways of doing things that produce less externalities. And that's why we disagree.

Also, note that externalities are not necessarily anything at all to do with the environment. I'd argue that the billions of hours of unpaid labor of people driving themselves places is an externality of an auto-based transportation system, albeit one that is difficult to quantify in an honest fashion.

CroMagnon

Alon, I know of one proposed project where I've studied the DEIS in depth. Also, the new LA Gold Line extension's Final Environmental Impact Report predicted congestion to deteriorate on the street running portions. There are probably a few others--it depends on the utilization of the street and the availability of parallel routes. This issue is not that difficult to predict or expect to occur, so I'm a bit mystified there would be an assumption that it wasn't true some of the time.

Anonymouse, I'm not saying we're screwed completely. But again, creating longer trip travel times, whatever the mode, is not good for absolute economic growth--so I'm against spending money to do it.

CroMagnon

Oh, and IIRC, the new LA Gold Line has been panned for some of the reasons I mentioned here. Unless they've massively sped the thing up, it's still far slower than the anticipated speed inputs used in the FTA cost-effectiveness quotient. I was skeptical that it would average the 20mph predicted, and I was right.

Ben Smith

Once again, another brilliant post Jarret!

Wanted to add my take on who transit is for: Personally, I believe it should be for everyone, or as many people as possible. Transit just for "poor people" who can't afford a car creates more problems than it solves:

- Creates a social stigma around using transit ("I'm a failure of society because I have to take the bus")

- Allows for it to become a political hot potato (Conservative governments cut back funding and expansion, since only poor people use it)

- Allows quality of transport and air pollution to go hand in hand (the more money you make, the less environmentally friendly your mode of transport is)

With all that said, the reality is that once somebody has purchased a vehicle, in many cases it is hard to convince them to spend $2-$3 to take transit.

This is why transit speed and priority are important, and how it plays into congestion. Let's say you have an at-grade metro line running down a highway median. Like most rapid transit lines, stops are placed every kilometer or so. Let's pretend this is its first day of operation and it is empty, while the highway is bumper-to-bumper. So while drivers are going nowhere, to their left is a train soaring right by them.

So the next day 90% of people take the train. The highway is no longer congested and is wide open, but this rapid-transit line still must stop every kilometer... So transit in this case is not a cure for congestion. Transit works best to feed and move people around areas which could not be sustainable if everyone drove. Ultimately, transit requires some level of congestion to remain competitive.

Does this mean we should write off transit as a means to solve congestion? No, but it does mean we should rethink which modes suit which needs. In the example above, I used a metro with average stop spacing. While this line may not have been competitive with the highway, it certainly could be with city arterials with frequent stoplights. Likewise, a commuter rail line with spaced out stops allowing the train to travel at high speeds above what one can drive (legally) can provide a competitive solution to highway congestion.

So in conclusion, BRT, LRT, or HRT should be used to reduce vehicle congestion for city streets. While commuter rail and express bus lanes can be used to reduce congestion on highways.

Alon Levy

CroMagnon, sometimes when you open a new link in a network, more congestion occurs - see for example Braess's paradox. However, well-planned links generally avoid it, which means that transit lines that actually get built, as opposed to merely proposed, almost certainly reduce congestion.

CroMagnon

Well, not all projects are well-planned, Alon. What can I tell you? There is simply no reason a priori that transit will automatically reduce congestion. You are arguing an untenable position.

Everything with transit is case by case. It is simply unsound to assume broad tenets are absolute, which is why I disagree with some of Jarrett's points here.

Ron Kilcoyne

For several years I have been saying that transit is an “alternative to congestion”. If you have a fixed guideway or preferential treatment for transit vehicles and can move faster or more reliably than autos in mixed traffic you provide individuals with an alternative to getting stuck in congestion. In these cases congestion is good for transit. It addresses the desire to rid our cities of congestion without making claims that can’t be honored.

I just heard an interesting thought at a conference I was just at. Improving vehicle fuel efficiency could have the same impact as widening roads – increased VMT that offset the fuel saved and emissions reduced from the technological advancement. Why? Because it will become cheaper to drive. This person was using this as an argument for transit as critical for reducing energy consumption, reducing greenhouse gases and improving air quality as a counter to those who view technology alone can address these issues. (Of course you need land use and design that supports walking, bicycling and transit as well as high quality transit.)

VR

Steve and Michael,

The Portland MAX (light rail) is not the problem, nor is streetcar. And Yes, I do understand the "system", Understanding the "system" in Portland is what I do for a living incidentally...

The only problem with the MAX or Streetcar is that the Portland region gets money from the feds or other sources for capital (construction) but none (or very very little) for operations or maintenance. This is what needs to change, because we can't keep building rail lines with capitol then have to sacrifice bus service to pay for the operation of the new rail lines.

It has nothing to do with the technology used, it has to do with how the funding is applied.

And rail (streetcar or light rail in this case) is not expensive. In fact, it is very cost effective. Rail lines and vehicle are very cheap to operate and maintain compared to roads and busses. So you pay a bit more up front but save lots in the long term. And trains last essentially forever if maintained. We still use the original 1980s light rail vehicles. How many busses from the 1980s are still in use?

And I agree with the fact that we do fail some of our areas, the Rivergate and other industrial areas that were specifically mentioned. We absolutely fail those areas - and I have been pushing the local and regional governments, and TriMet - to provide better service to the industrial areas because many people there who perform shift-work or other odd schedules have no recourse but to drive a car. We should be running busses out to industrial areas 24 hours a day, because those worker often need to get to/from a plant or factory before our regular bus service even starts for the day.

And yes, older Portland neighborhoods are more livable than new ones. But it has nothing to do with Metro. Older development has much more mixed use and has a much better street grid. I live in one of the old developments in North Portland. And I can walk to stores, libraries, Dr. Offices, restaurants, and whatever else you can think of. I have three bus lines and two MAX lines within walking distance. If I hop on my bicycle I can ride to just about any job, service, or destination easily and if not I can hop on MAX or a bus. All in a neighborhood that is over 100 years old.

Metro does not design neighborhoods (again, I know intimately - I work with them professionally). So I am not sure what asphalt steel and concrete areas you refer to that are Metro's fault. Metro does transportation planning, which includes roads and highways (in fact we spend way more time and money working with them on highways than any other piece). Metro also does land use planning, where they designate zoning guidelines and plans - which then are implemented by the local jurisdictions. Local jurisdictions are completely able to ignore Metro's plans, but they also may not receive federal dollars which are required to be administered by a MPO - which is what Metro is for us. Metro also does recycling/garbage and runs the expo center and convention center. I don't know how you can blame metro for any neighborhood designs - that is all local jurisdictions and developers.

Again, the Portland transportation system is by no means a failure. Of course - It absolutely can, and should be, improved. But all your rhetoric and hate for rail, does not make your so called "facts" (which you have not ever actually presented any "facts" - only your opinions) any more real.

Simply because there are still weak spots, does not mean it is a failure. And I do agree that we should fund more bus service. That is a long standing problem with our funding mechanism.

Any time anyone makes blanket statements like "Portland failed" it instantly shows a political agenda. There is no black and white like that in the real world. The way it actually works is that some things might be going well, and others could use improvement, and still others should be cancelled.

And I do use MAX, Streetcar, and bus service almost daily - as well as walking and bicycling, and driving (I own two cars and several motorcycles). So I have experience with all the modes. I even take airplanes and Amtrack from time to time when I travel, and have family members involved in the freight mobility industry.

I suggest, if you both are so down on Portland, that you go live somewhere else that doesn't have a transit system like Portland's and see how it works. I have lived all over the country. Southern California. Texas. The Rockey mountains. Several cities in the South. Some of them work well, some of them don't. And in each one there are plusses and minuses. The only ones I would say are "failures" are the ones with no transit systems at all. But Portland fares very very well by comparison to most US cities.

anonymous

To VR:

Are you sure about the public transit system Portland, U.S.A. has? And how does the system work that much? Are the railway lines (both heavy-rail and light-rail), bus, others working well so much? Please tell me the truth right now.

It is time to be realistic for how the various public transport systems actually work and, more importantly, which ones are appropriate to the circumstances not just in the U.S. but also around the world. Make sure you have to pay attention very well. Thank you.

Fr: anonymous reader

The comments to this entry are closed.

the firm

Jarrett is now in ...

Related Posts Plugin for WordPress, Blogger...
Related Posts Plugin for WordPress, Blogger...