Induced Traffic Induces More Support

Induced traffic has been a regular topic of this blog, most recently three months ago when I wrote about peak spreading, a first cousin to induced traffic.

But induced traffic, the well-founded theory that road capacity creates car trips regardless of population changes, bears regular revisiting because its implications are a key motivating force behind walkable urbanism and because it’s non-intuitive to many (including me at one time), requiring repetition for its lessons to be assimilated.

And when better to revisit induced traffic than when there’s good news to report?

We’ll start in Houston, Texas, where, as reported in CityLab, the mayor came out strongly with the argument that more traffic capacity doesn’t solve congestion and may make it worse.

In words I’ve taken from the CityLab article, he opposed a possible freeway widening by saying, “This example, and many others in Houston and around the state, have clearly demonstrated that the traditional strategy of adding capacity, especially single occupant vehicle capacity on the periphery of our urban areas, exacerbates urban congestion problems.  These types of projects are not creating the kind of vibrant, economically strong cities that we all desire.

Even better, the mayor won his office with a platform that included support for all modes of transportation other than single-occupancy vehicles, showing that Texas voters are willing to grasp the flaws of conventional traffic planning.

But the mayor’s continued endorsement of the theory of induced traffic doesn’t mean that the battle is won in Texas.  On the same day as he stated his opposition, the Texas DOT expressed their intention to reduce congestion by continuing to add lanes, including a widening of the freeway to which the mayor was referring, a freeway that is already 26 lanes wide.

Moving to California, Caltrans has released a policy paper acknowledging the validity of induced traffic and the reality that more roads often don’t ease congestion.  Not surprisingly, the consensus of the planners hasn’t yet filtered down to the rank-and-file, with those who rely on continued freeway projects for salaries and eventual pensions continuing to doubt the induced traffic phenomenon. 

Coming closer to the North Bay, a Silicon Valley mobility guru, acknowledging that we can’t build our way out of traffic congestion, convened a group of transportation experts to rate other methods of addressing congestion.  The top three were higher gas taxes, charges for single-occupancy vehicle commuting, and vehicle mileage taxes.  I’ve previously written about the first and last, while also supporting the discouragement of single-occupancy commuting.

Lastly, California recently issued long-anticipated draft rules requiring that environmental impacts of car travel be measured by incremental vehicle miles traveled rather than intersection level of service, a paradigm shift that implicitly acknowledges the reality of induced traffic and is a more reasonable measure of environmental impact in an era when climate change is the governing concern.

Despite the explicit direction of the legislature to make the change, the rules haven’t progressed quickly, with the entrenched road-building constituency pushing back.  Nor are they likely to proceed quickly from here, but issuance of the draft rules is still a milestone to be marked.

I won’t argue that we’ve reached a tipping point on induced traffic, but we’re moving in the right direction on fronts in Texas, Sacramento, and the Bay Area, all of which should be considered good news.

In my next post, I’ll return to a point that I made in passing a few posts back, about weighing the credibility of widespread municipal corruption versus a systemic shortcoming in the U.S. land-use model.  I’ll invoke a 14th century logician and Sherlock Holmes to make my point.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)

Induced Traffic, Congestion, and Peak Spreading Redux

I’ve written often about induced traffic and its near cousin congestion.  But they’re topics for which the lessons are non-intuitive and therefore bear frequent repetition.  There were times in my life when I would have looked askance at the concept of induced traffic and been in personal need of recurring lessons.  (I’ve learned to be more humble about my intuition.  The world is often more complex and counterintuitive than my instincts tell me.)

I’ve had conversations with folks to whom I carefully explained the phenomenon of induced traffic, including how it makes congestion almost impossible to solve.  The other parties nodded knowingly as I spoke, apparently following the thread of the argument just fine, and then, as their first question after I finished, asked “So what new roads must we build to solve congestion?”

Luckily, there are plenty of folks who are eagerly accepting the challenge of explaining induced traffic, including the answer that, within practical limits, there are no roads that will solve congestion.   (For the benefit of those in Petaluma, the answer has significant implications for the on-going Rainier Crossing discussion.)  Today, I’ll share the work of a couple of those folks.

Writing in Wired magazine, and a veteran of the Los Angeles freeways since early childhood, Stuart Dee reviews the current academic thinking on induced traffic, reporting the finding that traffic seems to increase in lockstep with newly constructed road miles.

As Dee summarizes the conundrum, “… we humans love moving around. And if you expand people’s ability to travel, they will do it more, living farther away from where they work and therefore being forced to drive into town.  Making driving easier also means that people take more trips in the car than they otherwise would.”

Dee’s solution is one that I’ve previously endorsed, congestion pricing, which is a modulated approach to a vehicle mileage tax.  Drivers, faced with a steep fee to drive through a particular location at a specific time, let’s say the financial district of San Francisco during the working day, will look for options to make their trip at another time.  If even just a few drivers adjust their trips, traffic congestion would ease and the streets would be more efficiently used for more hours of the day.

Looking at the same problem but from a different angle, Chuck Marohn of StrongTowns, based in Brainerd, Minnesota, likens a hierarchical road system, with local streets feeding onto collectors feeding onto arterials, to a water basin, with brooks feeding into streams feeding into rivers.

Marohn notes that downstream flooding is almost always the result of too much water escaping the upper elevations of the basin and overtopping the riverbanks in the lower elevations.  He then argues that the same is true of traffic systems, with too many trips congregating on the arterials where they become congestion.

The current regulatory approach to flooding is to require strict controls on the outflow from new development, typically through detention or retention.

Marohn contends that same approach would address congestion.  He argues that we need to build neighborhoods from which car trips never reach the arterials or in which daily tasks can be accomplished without cars.  In Marohn’s words, "For nearly seven decades, our national transportation obsession has been about maximizing the amount that you can drive.  We now need to focus on minimizing the amount you are forced to drive."  Luckily, we know how to do the latter.  It’s urbanism.

Two insightful writers with different life histories and different lifestyles looking at induced traffic and congestion and reaching similar and complementary solutions.  I use find that a sign of a fundamental truth, which beats the heck out of flawed intuition.

Before closing, I should note a related concept I recently came across.  At a public meeting of the Sonoma County Transit Agency, I asked a couple of SCTA planners and traffic engineers about their thoughts on induced traffic.  They admitted that their task was more the building of roads, but they were nonetheless well aware of the induced traffic phenomenon in their work.

But rather than calling it induced traffic, they called it “peak spreading”.  Their observation was the drivers who had time flexibility and an unwillingness to spend time in traffic adjust their travel times to drive or after the known peak time.  As a result, the duration of peak traffic gets longer over time.

I can confirm the description.  When my wife and I have a late afternoon appointment in Marin County, we make plans for dinner and perhaps shopping afterwards, preferring to burn a couple of hours rather than sitting in traffic.  We are induced not to travel during peak congestion and instead induced to travel at a slightly off-peak time.

And of course, the SCTA observation of peak spreading gives a window on the future when the third lane of 101 is built between Novato and Petaluma.  Rather than peak congestion diminishing, the principal effect will be reduction in its duration.  And then the duration will re-expand as induced traffic takes advantage of the new lane.

It’s a painful, but quite real, truth.  We’re not going to build our way out of congestion.  We’ve had a nearly hundred years of trying and it just doesn’t work.  Not only is the failure empirically evident, but we now have a theoretical basis that confirms the empiricism.  And we have solutions, in congestion pricing and urbanism, to better manage congestion.

Do I think that all readers now fully grasp induced traffic and the resulting congestion?  Nope, I know that counterintuitive realities take time to gain a foothold.  But I’ll keep sharing the work of engaging writers like Dee and Marohn and hope to someday have worn away the granite of flawed intuition.

In my next post, I’ll muse upon a discussion from a recent hearing I attended, a discussion that led me to think that too many of us have forgotten what it’s like to be a kid.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)

Rainier Connector: Why Not Now?

In my last post, I wrote about a topic that was to come before the Petaluma City Council on the evening of August 3.  The Council will decide whether the Final Environmental Impact Report (FEIR) for the Rainier Connector, a proposed arterial that would augment the traffic grid in the northwestern quadrant of town, meets the standards for environmental studies under the California Environmental Quality Act (CEQA).

In the post, I explained that I was frustrated by two aspects of the decision.  First, I was disappointed that the traffic section of the FEIR relied on older standards that will soon be replaced by legislatively-mandated regulations that will better reflect current thinking on traffic generation and climate change.  While I understood the need to complete the FEIR on the current schedule, it was still frustrating to see Petaluma disregard the best available approach, particularly on climate change.

Second, I thought that the Connector wasn’t yet ripe for construction.  While there is an argument for soon building a small segment of the Connector, the underpass beneath Highway 101 that can be constructed more efficiently if done simultaneously with upcoming freeway widening, my urbanist thinking says that the remainder of the road isn’t needed for years.  However, the inclusion of the entire Connector in the FEIR, and the process that requires the Council to vote the entire FEIR either up or down, precluded that level of nuance in the decision.

I remain comfortable with both of my conclusions.  And yet I judged that, despite my reservations, I would probably vote for the FEIR if I were on the Council, primarily to keep the underpass moving ahead.

However, from comments received, I also understand that I could have also dug deeper into the subject.  It’s a problem which I often encountered in writing this blog.  To my eyes, urbanism is a glorious multi-dimensional quilt with the various elements connecting in weird and wonderful ways, many of which I’m still working to fully grasp.

In a blog post, I focus on a tiny patch of the quilt, trying to explain the pattern to the readers while also sometimes adding a stitch or two of my own.  But at the same time I need to explain how the patch fits into the nearby areas and into the entire pattern.  And I need to do so without consuming the entire length of the post or exhausting the attention span of readers.

It’s a challenge for which my writing skills are often inadequate.  Hence, the occasional need to go back and fill in more detail to what I’ve already written.   This post, and the next one, will be in that mode.

Today, I’ll tackle the question of why building the Connector now would be premature.  It’s a subject on which I’ve written in the past, but I understand that many readers aren’t interested in returning to long ago posts, so I’ll provide an update here.

There are two principal reasons why building the Rainier Connector now would be a mistake.  One is induced traffic.  The other is maintenance.

The theory of induced traffic argues that roads create trips.  I know this seems absurd at first blush, but it really does appear to be true.  Let me ask a pair of questions.  Have you ever thought that you’d like to travel to the other side of your town, but didn’t want to drive in traffic, so deferred your trip until later?  If there was less congestion, perhaps because a new route had just opened, might you change your mind and take the trip now?  I expect that most of us would answer yes to both questions.  Congratulations, that makes all of us participants in induced traffic.

Research has shown that up to half of all new traffic capacity is consumed on the day the ribbon is cut.  And that much of the remaining capacity of consumed over the next decade, even in the absence of new development.

The implication is that congestion relief won’t happen.  Instead congestion will return to current levels over the next decade.  More people may travel between the east and west sides of town before congestion occurs, but that is about the only real benefit for the $90 million project cost.  If the primary motivation for building the Rainier Connector is congestion relief, then it shouldn’t be built.

Furthermore, as congestion reasserts itself, there would be opposition to new development on the grounds of traffic congestion, even though that new development is projected to help pay the debt from the Rainier construction.  It would become a Gordian knot.

And really, the story is even worse than that.  Let me use Friedman’s as an example.  (For those not in the North Bay, Friedman’s is a regional chain analogous to Home Depot or Lowe’s, but better.)

I love the fact that Friedman’s has returned to Petaluma.  Indeed, of the two recently opened Petaluma shopping centers, Friedman’s is the only business that I truly welcomed.

But I also love Rex Hardware in downtown Petaluma, relatively convenient to my home.  Rex is a cozy 90-year-old business that still sells individual screws, my personal measure of a good hardware store.  For most purchases, especially the smaller ones, I go to Rex.  (I’ve already visited there once today.)  Yes, I pay a little more, but I save time and travel costs.  I also have access to folks who give great advice.

 But imagine if the Rainier Connector was built, creating a few years in which congestion might be less.  More folks would likely trek across town to Friedman’s, looking to save a few dollars compared to Rex.  Seeing the business loss, Rex might decide to finally close their doors, leaving as the only option a drive across town to Friedman’s, creating yet more traffic as congestion reasserts itself.

And Friedman’s/Rex is only the hardware element of local retail.  Consider all the other retail segments that make up a community and imagine all the additional car trips that would created as the retail options lessen.

Managing congestion means encouraging neighborhood businesses that require few or no driving miles, not building streets that allow people to more easily bypass those businesses.

 The maintenance issue relies on a more intuitive argument.  From the day roads are built, they need maintenance.  Upkeep is essential is get good service over the life of the road.  I don’t have a good estimate of the maintenance costs for the Rainier Connector, but at least $100,000 per year seems a reasonable low-end guess.  Petaluma doesn’t have the funds to maintain its current roads.  How does adding $100,000 to a failed bottom line make sense?

I still believe that someday Petaluma will need the Rainier Connector.  The coherency of the traffic grid requires it.  But that someday should be when the town has many more people and the Connector is needed to give those folks logical routes of travel.  Someday isn’t today.

In my next post, I’ll write about what urbanism offers as an alternative to building new arterials.  I’ll offer both a view of the big urbanist picture that applies everywhere and a series of thoughts that apply specifically to the Rainier Connector.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)

Rainier Connector: When Neither Yes nor No Meets the Need

If memory serves, I was nine years old when my father introduced me to the possibility of questions having implicit but flawed propositions.  The example he used was “Have you stopped beating your wife?”  Because our brains perceive a simple yes/no answer as acceptance of the proposition, questions like this put the responder in a quandary, unsure how to disavow the incorrect premise.

(As a necessary digression, I’ve reported my father’s example question solely as a matter of historical accuracy.  It truly was the example he used.  But I’ll acknowledge that the question clanks on 21st century ears.  I don’t know what has changed since 1962, whether it’s our sense of humor, our sense of irony, or our acceptance of violence, but I still find it odd that my quiet, reserved father, who saved his ire almost exclusively for home improvement projects gone awry, used that particular example.  I can only assume that he was tone-deaf when he heard someone else use the example.

I’ll also note that other questions can illustrate the point equally well.  “Have you quit beating your husband?”, “Have you quit teasing the family dog?”, “Have you quit fudging your workout log?”, and “Have you quit cheating on your taxes?” are all examples.  In recognition of one element of the ongoing financial crisis in Greece, I’ll use the last for the remainder of this post.)

I mention this peculiar intersection between grammatical form and human cognition because a question with elements of “Have you quit cheating on your taxes?” will soon come before the Petaluma City Council.

I’ve written before about the Rainier Connector, a proposed Petaluma arterial that, although short in length, would be long in cost.  In its length of under a mile, it would pass beneath Highway 101 and over both the Petaluma River and the railroad mainline, all of which adds greatly to its estimated bottom line.  The estimated cost varies depending on assumptions about design and cost sharing, but $90 million is a commonly used number. 

Although a funding source for the Rainier Connector remains unknown, with voters having recently rejected two separate sales tax measures that would have provided at least partial funding for the project, the Petaluma Planning Department has been proceeding with the environmental impact process.  This work has been undertaken because of a need to align with an upcoming freeway design effort.

With the public vetting of the environmental studies now nearly complete, the Final Environmental Impact Report (FEIR) is scheduled for consideration by the City Council on Monday, August 3.  The question that is implicit in the consideration is whether the FEIR adequately addresses the environmental impacts of the roadway project consistent with the provisions of the California Environmental Quality Act (CEQA).

This is the question that I find has much in common with “Have you quit cheating on your taxes?”  Neither yes nor no seems to meet the need because the question contains implicit propositions that I desperately want to disavow.

In my comments, I’ll write solely about the traffic impacts of the Connector.  It’s the aspect of the project with which I’m most familiar and about which I’ve often written, including here, here, and here, when I offered an urbanist perspective on the traffic issues around the project.

I know there are other important environmental issues, such as the impact of the river crossing on potential flooding, the effects on flora and fauna within the floodplain, the potential for erosion, construction noise, and many others.  All of those issues undoubtedly will be considered by the Council, but traffic is where I’ll focus today.

The traffic analysis in the FEIR shows traffic improvement at most intersections, with the only exceptions being the intersections approaching the Rainier Connector.  The improvements are more minor than many may have expected, but that’s largely the result of baseline traffic being expected to continue increasing between now and 2020, when the new roadway might be completed.

So far, so good.  But here’s the problem.  The traffic analysis was done using intersection level-of-service, an approach that has been used for decades, but is now increasingly perceived as being more about moving cars across town than people and is being steadily replaced in environmental studies by vehicle miles traveled, an approach that incorporates both greenhouse gas emissions and induced traffic.

Among the agencies that have adopted the new approach is the State of California, which sets the CEQA standards.  However, at last report, the state was still working on the rules to implement the new traffic study method.  Until that task is complete, cities such as Petaluma may continue using the soon-to-be-supplanted level-of-service standard.

Other California cities, notably Pasadena, eager to embrace the new model and to begin managing traffic growth with an eye toward climate change, have adopted their own rules in advance of the state.  But Petaluma chose not to follow that path, clinging to the old rules and publicly expressing skepticism about the new rules.

And so this is where we start entering the anomalous world of “Have you quit cheating on your taxes?”  Is the FEIR consistent with CEQA?  Probably, at least with regards to traffic.  But the CEQA rules are outdated and soon to be replaced.  And it’s hard to feel good about being consistent with obsolete rules, especially when the impact of following the old rules is increased risk of climate change.

Indeed, it’s likely that the roadway would fail the new vehicle miles traveled standard because the Rainier Connector will increase the number of vehicle miles traveled.  But the yes/no dichotomy being presented to the City Council doesn’t allow for exploring that possibility.

(Time for another digression.  Petaluma holds an anomalous role in the world of urbanist planning.  Among the first places, along with the State of Oregon, to adopt Urban Growth Boundaries as a planning tool and the very first to implement the cutting-edge SmartCode to direct urban development, Petaluma is sometimes perceived as a progressive planning community.

But that perspective ignores the rest of the history.  The single-family housing sprawl that continued even after the first Urban Growth Boundary was adopted.  The flawed drafting of several key provisions of the SmartCode that hamstrung urban developers, missteps that have only recently been corrected.

Petaluma’s planning history is known by many for its bold steps into the future and by others for its bumbling follow-up to those steps.

Planning for a $90 million roadway using traffic criteria that have already been disowned by much of the world, including the State of California, seems to align with the bumbling side of the Petaluma equation.)

Further complicating the yes/no calculus is the reason that the FEIR is coming forth at this time, far in advance of construction funding.  Without an approved FEIR, Caltrans can’t accommodate the Rainier underpass in the design of the widening Highway 101 that could perhaps occur in the next few years.

And, in my opinion, Petaluma truly does need the Rainier Connector.  It doesn’t need the new road today, but I suspect that the Rainier Connector may well be an essential element of the local transportation grid someday, perhaps in 2075 when the local population is 125,000.  By then, the roadway could be a vital path to provide efficient routes for city buses, to strengthen the bicycle network, and to connect people living in homes that haven’t yet been built to businesses that don’t yet exist.

But in 2075, it may be prohibitively expensive to build an underpass beneath an existing freeway.  So it’s reasonable to build the underpass today, making it available for the future time when it’s truly needed.

Pushed to make my own decision, and with my only choices being yes and no, I’d probably vote in favor of approving the FEIR.  But the vote would come with a strong caveat that I’d have no interest in building the Rainier Connector at this time, except for the freeway underpass.

I suspect that an alternative FEIR, one that addresses the question of building the underpass in the next decade, but not building the remainder of the road until a date that may be a half-century away, would meet even the coming CEQA traffic standards.  And I would expect it to be a FEIR that I could support whole-heartedly.  But that’s not the question before the City Council.

Nor am I alone in finding myself conflicted by the decision as now presented.  When the FEIR was reviewed by the Petaluma Planning Commission, it failed to win approval on a 3-3 tie vote.  Since that evening, I’ve had the opportunity to chat with a couple of the Commissioners who voted against approval after long and difficult consideration.  I’m proud to have fellow community members who worked so hard on the issue and voted the way that their heads and their hearts told them was right.

Does it make sense to laud Planning Commissioners who reached a different decision that I suspect I would have?  Not really.  But that’s what happens when we pose yes/no questions with flawed propositions.

I expect an interesting City Council meeting on the 3rd.

Meanwhile, yes, I’ve quit cheating on my taxes.  … I mean no, I haven’t quit cheating on my taxes.  …  No, no, no, what I mean is … Well, nuts.

In my next post, I’ll add one last detail to my thoughts on the Rainier Connector, an example of how flawed decision-making inevitably builds upon itself.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)

Induced Traffic Comes in Different Flavors

On several earlier occasions, I’ve written about the phenomenon of induced traffic.  In one post, I used a hypothetical Yosemite campground to illustrate the theory.  Several months before that, I yielded the floor to walkability expert Jeff Speck for a video explanation of induced traffic.

But for those who aren’t yet familiar with the concept, I’ll offer this short explanation.  Drivers have a limited tolerance for congestion.  When they encounter congestion above their tolerance, they find another route, defer their trip to another time, or redirect themselves to a less congested destination.

Therefore, when new traffic capacity is provided, perhaps through the construction of additional travel lanes, drivers who were previously avoiding trips began again to take those trips.  The result is that congestion, after an initial drop, soon returns the same level that it had before the construction, even in the absence of new development creating new trips.

This is a non-intuitive result that conflicts with our instinctive expectation that additional traffic capacity should result in reduced congestion.  But if we seriously consider our own travel decisions, deferring trips when possible to avoid congestion, the validity of the theory soon becomes clear.

This is also where I mention Robert Moses, who grabbed the reins of New York City public works and held them for more than four decades through the middle of the 20th century.  Moses was known for claiming that just one more expressway, freeway, or bridge would make New York City traffic flow freely forever.  He passed away still believing the argument, having failed, despite forty years of contrary examples, to have realized the error in his thinking.

Luckily for us, the lesson that eluded Moses has finally been grasped in the years since his passing.  As I’ve previously written, California is changing its environmental assessment rules to reflect the reality of induced traffic.  And there is a wealth of research and writing spreading the story of induced traffic.

Writing in City Lab, Eric Jaffe offers a simple graph showing the induced traffic effect.  And he notes that the only solutions that can seriously address the phenomenon are transit, transit-oriented development, and congestion pricing.

In Wired, Adam Mann also takes a look at induced traffic, reporting the work of researchers who note that the reverse of induced traffic is also true, that reducing travel lanes doesn’t necessarily cause additional congestion.  (Referring back again to Robert Moses, those who have studied the tussles between Moses and pioneering urbanist Jane Jacobs, may recall their fight over Moses’ plan to run an expressway through Washington Park, claiming that the failure to do so would result in gridlock.  Jacobs won the battle, Washington Park was preserved, and congestion didn’t noticeably change.  It should have been a lesson to Moses, but he wasn’t good at lessons.)

Mann also reports the warning that induced traffic may only be true over a limited range of traffic conditions, although the range likely covers most real world situations.  If a city were to take a two-lane Main Street and convert it to a ten-lane thoroughfare, it’s likely that congestion would be slow to return.  But it’s also likely that the downtown would have been destroyed.

Into this increasing understanding of induced traffic, Adam Millard-Ball, a professor at the University of California, Santa Cruz, notes that, even before considering induced traffic, many of the trip projections for new development may be flawed.

Writing in Access, the transportation journal of the University of California, Millard-Ball reports on his research into the trip generation rates reported by the Institute of Transportation Engineers, the bible on which most traffic studies are based.  He finds that the ITE numbers are consistently and significantly higher than the actual traffic generation results.

He points to several possible causes for the discrepancies.  ITE standards call for only successful projects to be measured, ignoring that a percentage of land development projects fall short of full success and therefore generate less traffic.  Also, the ITE only reports absolute trip numbers when marginal rates would give a better picture in many situations.  As an example, a new grocery store in an underserved portion of town might result in fewer vehicle miles traveled as shoppers can drive fewer miles to serve their needs, but the ITE manual only reports the absolute number of trips.

Combining the growing understanding of induced traffic and the Millard-Ball insights on the ITE numbers, yields a paradoxical view of a possible land development.  A hypothetical developer could be obligated to pay for traffic improvements based on ITE rates.  But when the project stumbles, fewer trips are generated.  However, induced traffic quickly claims the unused new capacity, resulting in congestion being the same as before the project.  The public now complains that city hall failed to require sufficient traffic improvements of the developer, even when the reality is that he was probably docked for too many improvements.

It’s a tangled mess, which only serves to reinforce the need, as noted by Jaffe, for congestion pricing, better transit, and transit-oriented development.

And to add one final twist, most of the analyses look at lane capacity as being the traffic improvement being claimed by induced traffic study.  But other traffic improvements could apparently also be subject to the same phenomenon.

Here in Petaluma, the intersection of E. Washington Street and S. McDowell Boulevard is the busiest intersection in town and is often heavily congested.  There are frequent public calls for improved signal timing, including a recent article in the Argus Courier noting the concerns about the intersection and reporting the comments of City staff on the signal timing options.

I have two comments on the story.  First, I know the City staff quoted and believe that they’re truly doing their best to improve the intersection.  But even more importantly, the traffic signals would be subject to the possibility of induced traffic.  Even in the unlikely event that a change could magically add 20 percent more capacity to the intersection, induced trips would soon claim that capacity, returning traffic congestion to its current level.

There are no easy answers.

Next time, I’ll add another insight to the E. Washington Street and S. McDowell Boulevard intersection challenge, an insight that has broad applicability and tells us much about how we view traffic.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)

The Futile Search for “Achievable Alternatives”: Why the Apparent Solution Fails

In my last post, I introduced a question from a correspondent about “achievable alternatives” for traffic congestion relief.  The particular question pertained to the congested E. Washington Street in Petaluma and the proposed Rainier Connector that many believe would provide relief, but the question could apply to overloaded arterials everywhere.

In the earlier post, I explained how E. Washington Street became congested.   I also presented the Rainier Connector as the apparent solution in the minds of many.  Today, I’ll try to offer an explanation on why that conventional wisdom is wrong.  In my next post, I’ll offer the alternative ways of thinking about traffic that are provided by urbanism.

The Problem with the Proposed Solution:  The reason that the Rainier Connector likely won’t provide significant traffic relief is induced traffic.  It’s a concept that I’ve noted before, but today I’ll try to provide a deeper and more complete explanation.

Economists have a well-evolved vocabulary for many of the concepts I’ll try to explain below.  But I’m not an economist and would likely trip over my word choices if I pretended to be one.  So I’ll write in my own lay words.  And if the economists among the readers want to recast my arguments into the economist dictionary, please do so.

The root of traffic congestion, and the resulting problem of induced traffic, is related to how public agencies set, or don’t set, prices on scarce resources.

In the private world, the free market system with its rules of supply and demand usually governs.  Given tee times to fill at a top-rated golf course, the green fees are set high.  If surplus demand still remains, the green fees are bumped even higher until the demand for tee times eventually matches the number of tee times available.  Given rooms to fill at a nice hotel, the same rules apply.  Diamonds to sell?  Same rules.  Adjust the price until supply and demand meet.

The supply and demand system is marvelously elegant and intuitive.  And for the most part, it works well.  Some may not like the answers that pop out, but the market usually tends toward logical and rational.

But we, as represented by our various levels of government, typically have an aversion to the applying the same market rules to public resources.  We don’t want the best camping places going to millionaires driving tricked out recreational vehicles.  And we don’t want to dole out hunting permits only to the well-heeled.

So instead, we devise a range of non-price systems to allocate scarce resources.  Have a campground that’s usually full all summer?  Institute a policy that requires advance reservations on a first-come, first-served basis.  Managing a trail that has excess demand?  Devise a lottery for hiking permits.  Afraid that unfettered fishing will exhaust a stream?  Implement rules like catch-and-release, closed seasons, and catch limits to reduce pressure on the fishery.

But there are also public resources to which we don’t choose to apply significant impediments.  At the top of that list is street capacity.  Given that most people already have cars and drivers licenses, the only barriers to driving extra miles, whether on open country roads or congested downtown streets, is the incremental vehicle wear-and-tear and the cost of gasoline, neither of which is a significant barrier.

To understand the implications of this absence of obstacles to driving, let’s try a thought experiment.

Presumably all are familiar with the scenic wonders of Yosemite National Park.  Access to Yosemite is well-regulated by entrance fees, high cost hotel rooms, advance registration campgrounds, and hiking trail lotteries.

But imagine if Yosemite management decided that the barriers to park use were too high.  To allow more folks to partake of the park, they clear a meadow on the valley floor, throw a fence around it, and open it to unlimited camping use.  No reservations, no fees, no designated camp sites.  Just an open gate.  People could pitch tents wherever they wished, with no standards about how far they needed to be from other tents.  (To be clear, I’m not suggesting this idea.  I’m only offering it for thought purposes.)

What would happen?  Obviously, the campground would fill quickly and campers would soon be stepping on each other’s toes.  Some campers would give up and go home, deciding that a vista of Half Dome wasn’t worth being unable to warm one’s hands at one’s campfire without burning one’s backside on a neighbor’s campfire.  But plenty of campers with a high tolerance for crowding would remain.

Now let’s say that Yosemite management, looking at the “success” of the new campground, decided that the concept was valid, but that the overcrowding had become too burdensome.  To allow more spacing between tents, they decide to open a second campground with the same set of rules, arguing that the density of campsites will thereby be halved.

But that’s not what would happen.  Remember the campers who went away, turned off by the lack of space between tents?  They’d come back, happy to camp with even a little more space.  The congestion in the second campground would quickly rise to nearly the same level as the first campground.

Obviously, there would some number of campgrounds that would satisfy the demand for cheap, no-frills Yosemite experiences, but the entire valley floor might be consumed before that point is reached.

And that’s exactly what happens with congested city arterials.  Some may argue that traffic congestion would disappear with new road capacity, but the reality is that campers, I mean drivers, who had previously deferred trips would return to congest the new roadway.

Nor is this a hypothetical supposition.  Study after study shows that a large chunk of new roadway capacity is consumed on the day it opens, with the remainder consumed in next few years, even in the absence of new development.

This finding is why the State of California is implementing new rules to judge environmental impacts based on traffic generation, not congestion.  Unwilling to await the new state rules, the City of Pasadena implemented their own rules to the same end.

(Side note: When the Petaluma Planning Commission reviewed the Draft Environment Impact Report for the Rainier Connector, some Commissioners noted the surprisingly small congestion relief benefits projected as a result of the new road.  But under the pending revised California rules, which measure traffic generation in place of congestion relief, the balance would make the outlook even worse.  Instead of a minor benefit, the traffic impacts of Rainier Connector would be judged a negative.)

So when the correspondent asked about “achievable alternatives”, his underlying supposition was flawed.  Not only are there no achievable alternatives, but even the preferred solution of the Rainier Connector wouldn’t provide the promised benefits.  Induced traffic undermines any attempt to reduce traffic congestion by building new roads.

Urbanism can’t solve the problem of induced capacity, but it can offer a different land-use paradigm and set of tools that would make traffic congestion less of a daily problem.  The paradigm and those tools will be covered in my next post.

Schedule Reminder

The meeting of Petaluma Urban Chat to take a renewed look at the Sonoma Marin Fairgrounds is rapidly approaching.  It’ll be Tuesday, November 11.  To accommodate the anticipated larger than normal attendance, the meeting has been moved to Taps at 54 E. Washington Street in the River Plaza shopping center.  We’ll convene at 5:30 and likely conclude shortly after 7:00.  Please be on time because the evening is expected to be full.

Some have asked about a recap of earlier meetings.  The topic of the fairgrounds was originally broached back in July.  As the early meetings progressed, two updates were provided here and here, and then a couple of points required clarification.  The coming meeting won’t necessarily build on the earlier meetings, but familiarity with the previous conversations may be useful.

I look forward to a successful meeting and to chatting with many of you.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)

Jeff Speck on Induced Traffic

An aspect of urbanism that I love is how the land-use pieces fit together in complex but comprehensive patterns.  It’s the antithesis of drivable suburban development where houses can go in one block, retail a half-mile down the street, and an office park a couple of miles away.

In urbanism, the pieces of life can’t be as easily separated, but must live in symbiotic relationships, whether walkable distances apart or easily connected by transit.  Cars can’t be used as band aids for ill-conceived land-use patterns.

Because of the essential connectivity of urbanism, urbanism experts can’t stay in silos.  Unlike drivable suburbia where there can be shopping center architects, residential architects, traffic engineers, and other diverse specialties working in near isolation, urbanism experts must cross boundaries all the time.  Urbanism is more like puzzle-solving, which is way more fun than complying with lists of rules.

Today’s example of a multi-faceted urbanist is Jeff Speck.  I’ve written often about Speck and his book “Walkable City”.  Through the book, he justifiably became nationally known on walkability issues.

But walkability isn’t his only strength.  Indeed, it can’t be.  Like every other urbanism expert, he must have an understanding of the other areas of urbanism that touch upon his primary area.  Other areas such as transit and traffic capacity.

As a result, Speck recently spoke before a large conference in Mexico City on the subject of induced traffic.  As always, his presentation was comfortable, but also profound.

However, you needn’t take my word for it.  You can watch for yourself.  Allow about fifteen minutes.  It may be the most insightful fifteen minutes of your day.  Especially if you pay particular attention to his comments on congestion and how traffic reacts to it.  The fact that traffic adjusts to maintain the same level of congestion is the heart of induced traffic and why we can’t build our way out of congestion.

Don’t be deterred by the Spanish text on the webpage.  Speck speaks in English, although with Spanish subtitles.

Enjoy.  And be educated.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)

City Repair Debriefing Plus Notes on Induced Traffic, Broadway, and the Movies

It’s Friday and we’re moving closer to the holiday season.  No big topics today.  Just a grab bag of follow-ups and loose ends.

City Repair Petaluma: The long-planned City Repair Petaluma meeting was held earlier this week.  Attendance was good.  I counted at least 35 people, but couldn’t see the entire back row.  There was even a City Councilmember who attended for awhile.

After viewing the City Repair film and engaging in an extended question and answer session, City Repair Petaluma organizer Rachel Kaplan asked for ideas on neighborhoods where City Repair projects might be appropriate.

To our pleasure, representatives of several neighborhoods immediately responded, most of them also willing to help in the organizational effort.  The identified neighborhoods included D and Vallejo, D and El Rose, Mountain View and Mission, 2nd and F, Western and Webster, Western and Fair, and Oakhill-Brewster.

Individual neighborhood groups then met to exchange contact information and to begin tossing about ideas.

It remains a long ways from initial enthusiasm to completed project, but the self-identification of champions was a good step.  I believe that the City Repair process works best when the progress is slow and steady.  The Tuesday evening meeting was a great slow and steady start.  The process will continue.   And I’ll provide occasional updates.

And if anyone would like to be added to the City Repair List email list, please let me know.  I’ll pass along your information to Kaplan.

Induced traffic:  When I recently wrote about the proposed Rainier Avenue connector in Petaluma, I noted the phenomenon of induced traffic, an increase in car trips when new roadways are opened which prevent the promised traffic relief.

In response, I received only a couple of comments of mild skepticism.  Most readers seem to understand induced traffic.  But when I look at the local papers, I continue to read quotes, many of them from people who should know better, that Rainier will provide true traffic relief.

So it’s time to roll out a big gun.  Before the rise of Jane Jacobs, Lewis Mumford reigned as the monarch of urban study and thought.   Almost 120 years after his birth, he remains a key oracle on the theory of cities.

In 1953, Mumford wrote, “No one, it seems, pays heed to our own grim experience, which is that the more facilities are provided for the motorcar, the more cars appear.”

In the sixty years since Mumford wrote those words, no one has successfully rebutted them.  But many of our community leaders seem unaware of the wisdom.

If/Then: I love the field of urban planning, finding the process fascinating.  But that doesn’t mean that I would expect it to be ripe for a Broadway musical.

Perhaps I’ve been wrong.  “If/Then”, a musical about a 40s-something woman trying to rekindle her life as an urban planner in New York City, is currently touring the country in hopes of reaching Broadway.  And at least planners seem to enjoy it.

“Chasing Ice”: My wife generally does our household Netflix selections.  Last weekend, she came up with “Chasing Ice”, a documentary on the efforts of photographer James Balog to record the recession of glaciers throughout much of the Western Hemisphere.

It was an oddly scripted movie, shifting from the technology of time lapse photography in adverse climates to the disappointment in the initial photographic failures to Balog’s knee surgery to the presentation of the results at scientific conferences.

But despite the jumpiness, the movie worked.  The scenes on the glaciers were cinematically striking.  And the film was a stark reminder of the effects of climate change.  In my household, we moved directly from viewing the movie into a discussion of further carbon reductions we could make in our home.

Of course, urbanism remains one of the most effective strategies to slow climate change.  Of all the energy savings that we can make in our daily lives, nearly 70 percent can come solely from living in a walkable urban setting.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)

You Can’t Go Home Again – Part 1, Highway 97 in Bend

Returning to a place once known well, and now changed in ways both big and small, can reveal new truths about the place and the observer.  I was reminded of this during recent travels in the Pacific Northwest.

In past posts, I’ve made reference to my geographical past, although never in a comprehensive manner.  Perhaps some readers have assembled a complete picture of the places that I’ve called home.  But I should offer a biographical sketch to provide context to my recent travels. 

Born and raised in California, I had enough wanderlust that I didn’t want to spend my entire life in the Golden State.  In 1982, I transferred with my employer to Seattle, where I managed a water resources department.

For family reasons, I moved to a smaller town in 1987, picking the community of Bend in Oregon’s high desert, east of the Cascades.  Now with a different employer, I still worked in water resources, but also in land use.  I lived in Bend until I returned to California in 2000.

I retain strong attachments to Seattle and Bend.  Seattle, despite its weather and lack of diversity, remains my favorite big city.  Not that I dislike San Francisco, but I’d pick an afternoon in Seattle over a week in San Francisco.  There just something about the air, the streetscapes, and the neighborhoods that feels right.  I haven’t lived there in over 25 years, but when I set foot on a Seattle sidewalk, it still feels like home.

However, the connection to Bend is even stronger.  It was the first place where I felt fully integrated into a community and where I felt my contributions made a difference.

That isn’t to imply that I had great power in Bend because I didn’t.  I didn’t hold public office nor did I manage large resources.  But I sat on several local committees, provided engineering services for projects that changed the face of Bend, and could get my phone calls returned.  (This would have been in the days when phone calls were still the dominant way of conducting business.)

At one time, it seemed that I could walk in downtown Bend, especially in the non-tourism season, and have a nodding acquaintance with over half the people on the sidewalk.  It was a life I enjoyed.

And now I was heading back to visit both cities.  Every year, I join friends for a weeklong tour of minor league ballparks, breweries, and other assorted sites.  This year, we chose to visit the Pacific Northwest.

Over the course of ten days, I revisited the old places that were once so familiar to me.  And I was looking with eyes that were more attuned to urbanism.  It was ten days filled with surprises and urbanist observations.

Observation #1: Stroads can hide in plain sight - For many years, Highway 97 was the primary north-south route through Bend.  It was impossible to live in Bend without being on Highway 97 several times a week.

Despite that history, when StrongTowns introduced me to the word “stroad”, I never once thought of Highway 97.  (For those readers who aren’t familiar with the term, a stroad is a vehicular way stuck halfway between being a rural road and a city street.  It’s an uneasy blending of the two which results in a dangerous place to drive and an impossible place to walk.)

Upon my arrival in town, I drove Highway 97 to see what had changed along its route.  To my surprise, I realized that it was, and had always been, a stroad.  Although Highway 97 has sidewalks, they are unfriendly places.  I don’t recall seeing a single pedestrian during my recent visit.

Furthermore, the highway, which was already full of driveways when I lived there, now has even more driveways, with every driveway providing an opportunity for vehicular conflict.  (While in Bend, I spoke with an old friend who assured me that the state highway department access management group has been emasculated to the point that few driveway permits are denied.)

Highway 97 was an ugly place.   And a disappointing reminder of what we can overlook in our daily lives.  I drove on a stroad on a near-daily basis for 13 years, but never thought of the transportation failure I was seeing.

Observation #2: Induced traffic is real - I’ve previously mentioned induced traffic only in passing.  It’s a topic that deserves a complete exploration, but that will be at another time.  For now, I’ll offer a brief introduction.

The theory of induced traffic argues that drivers make decisions about taking trips and selecting routes based on the availability of traffic capacity.  At the simplest level, whether a driver makes an optional trip depends on whether the driver expects to encounter heavy traffic.

In real life application, the result is that new traffic capacity, whether from new lanes or new streets, is often consumed by non-essential trips.  Conversely, loss of capacity, such as from street closures or construction, often results in fewer trips being taken.  Congestion doesn’t remain static regardless of street capacity, but it’s closer to static than most older traffic models predict.

The theory of induced traffic is one reason that urbanists argue that we can’t build our way out of traffic congestion.  As long as a local economy remains active, new street capacity will be sucked up while providing little traffic relief.

A theory isn’t proved by a single anecdote, but I found a piece of supporting data for the theory of induced traffic during my visit to Bend.

Highway 97 was bypassed by the Bend Parkway during my final years in Bend.  The intent was to reduce traffic on Highway 97.  This was my first trip back to Bend with the Parkway in full operation.  I could have taken the Parkway, but choose to stay on Highway 97 to take a look at the town.  (This was when I realized that Highway 97 was a stroad.)

In the time I was away, Bend had grown, but only slightly.  Although it remains a popular tourist destination, population growth has been slight and property values had plummeted during the recent recession.

Under a conventional theory of traffic generation, traffic on Highway 97 should been far less than I remembered.  Total traffic growth should have been small and much of the previous traffic should have moved to the Parkway.  The prediction would have been wrong.  Highway 97 was bumper-to-bumper through much of Bend.  Induced traffic is alive and well in Bend.  Although I’ll wager that someone in Bend is arguing to add more capacity to deal with the congestion.

Next time, I’ll write about a Bend land-use decision in which I played a key, but unsatisfying, role.

As always, your questions or comments will be appreciated.  Please comment below or email me.  And thanks for reading. - Dave Alden (davealden53@comcast.net)