China Bans Reporting on Bridge Collapse

In today’s WaPo: China Bans Reporting on Bridge Collapse –
“Communist authorities have banned most state media from reporting on the deadly collapse of a bridge in southern China, with local officials punching and chasing reporters from the scene, reporters said Friday.”
Apparently physics works in both communist and non-communist countries; but a free press only in non-communist ones.

I 35W Bridge repair

Article from today’s Strib: Phone call put brakes on bridge repair
“Plans to reinforce the bridge were well underway when the project came to a screeching halt in January amid concerns about safety and cost.”

Is the 80:20 rule recursive?

The 80:20 rule is a heuristic that people use to suggest that 80% of the benefit comes from 20% of the effort (the values of the parameters may change, but the idea is that a relatively small share of effort gets a majority of the benefit). In one sense this is the idea of diminishing marginal returns, as the last 20% of the benefit requires 80% of the effort. This idea is related to the Pareto principle.
If this is true, the question arises: is the 80:20 rule recursive? Of the first 80% of benefit, does 80% of that only require 20% of the first 20% of effort? In other words, is there a 64:4 rule. Or worse, is there a 51.2: 0.8 rule. If so, then less than 1% of effort gets more than half the benefit.
That sounds like a really good deal to me.

Antecedents of Urban Sprawl

From LA Times: Angkor was a city ahead of its time .. the city had of about a million people spread over an area similar to LA before the industrial revolution.

Chinese bridge collapse kills 22

From BBC: Chinese bridge collapse kills 22

I-35 W Bridge Collapse, some initial thoughts

The I-35 W Bridge over the Mississippi River in Minneapolis collapsed at 6:05 pm CDT last night. The Strib reports: 9 dead, 60 injured, 20 missing after dozens of vehicles plummet into river
This is of course a tragedy for those directly involved. I myself was driving under the bridge earlier yesterday with family. Fortunately that was 3 hours earlier, and everyone in my immediate family is safe. It is of course shocking to think about this bridge that I have traveled hundreds of times (about 2 miles from my house) collapsing. Having just returned to Minneapolis about 36 hours ago (I was actually going to say something nice about Northwest Airlines), this was not the welcome I was seeking.
I have some random thoughts below,
== Network Effects ==
What will be the effects of the collapse on traffic?
Networks are complex things. MnDOT has suggested using the roughly parallel MN-280 as a bypass, and have (temporarily?) converted the road to a freeway by turning to green the only traffic light on the road (why was the light never replaced earlier?)
There are other possible substitutes, that MnDOT and the local neighborhoods will not want to encourage as bypasses. For long distance trips, the I-494/I-694 beltway, US-169, Mn 100, and I-35E will one suspect get additional traffic. (hypothesis #1).
For shorter distance trips, traffic that would have gone down I-35W may divert to Mn-280, Broadway to I-94, or Snelling Avenue (which is a limited access highway for a good stretch, and should be immediately have its traffic signals retimed to accommodate additional traffic)
It might take some time for a new equilibrium pattern of traffic to re-emerge. It is still summer vacation period, so the University of Minnesota has not started a full fall semester, and traffic levels are relatively low, giving some change to adjust. The day after Labor Day will be another time to test.
As a result of this however, some other problem sections of road may no longer be as problematic. The merge from I-35W sb to I-94 wb should not cause problems for instance (hypothesis).
There might be interactions with the Crosstown reconstruction, as that is also discouraging traffic from using I-35W a few miles south. It might make more sense now to consider just closing all of I-35 W so they can do the reconstruction faster (assuming closure would make it easier to do the construction under the current design).
== Reconstruction ==
Some recent bridge collapses (I-580 in the Bay Area) were remedied quite quickly. I think this will be longer. First it is a much larger bridge. Second, it will clearly require redesign, as the first design failed for “unknown” reasons (as opposed to a a truck exploding, which may not be worth defending against).
== Structures ==
I am not a structural engineer. This report by my late colleague Bob Dexter is interesting
Fatigue Evaluation of the Deck Truss of Bridge 9340
Robert Dexter, Heather O’Connell, Paul Bergson
March 2001
Report no. Mn/DOT 2001-10
Of course the abstract, while noting problems with the design,it said “As a result, Mn/DOT does not need to prematurely replace this bridge because of fatigue cracking, avoiding the high costs associated with such a large project.” This was published 6 years ago , probably finished 7 years ago, and things change. Reports in the news media say the bridge was structurally deficient. We still don’t know what element of the bridge failed first, or if the construction on the bridge had any role (one suspects it does, but that is still speculation).
== Politics ==
(1) Allocation of resources to new facilities rather than repair and maintenance.
This is a classic problem in transportation funding. Ribbon cuttings on new projects are much more politically “sexy” than maintaining what we have. People are also more interested in road surface than the underlying structure. Yet pavement failure, while bad, is not nearly as bad as structural failure. “Failure” in the traffic level of service sense, while economically costly and personally annoying, and perhaps leading to more (or at least different) crashes, does not have anywhere near the same connotation as structural collapse.
(2) Vetoing the gas tax
Minnesota Governor Tim Pawlenty recently vetoed a legislature-passed increase in the gas tax that could have raised money to repair bridges like this one. The latest gas tax would not have solved this problem, but previous taxes that were not passed (due in part to Pawlenty’s previous veto threat) may have, had the money been spent on this kind of thing.
(3) Pointing fingers
It is too soon to say “J’accuse”. Most people will probably want to wait for rescue and recover operations to be complete, and then for memorial services, and then for a more thorough investigation. However, MSNBC was starting early speculating in which direction the fingers would wind up pointing.
(4) Funding the stadiums
Minnesota is in the process of building 3 new stadiums (Twins, Gophers, and eventually the Vikings). Is this the best use of local funds? Hopefully this will be a shock to the system.
== U of Mn ==
Keeping with the University of Minnesota tradition, classes will go on today as scheduled. Classes were cancelled on 9.11, but that happened the same day.
== Crisis vs. Opportunity ==
Rebuilding the bridge is of course a crisis, but it is also an opportunity to do something interesting. I speak in particular of air rights. A bridge over the Mississippi is expensive. But imagine having a 2 or 3 story office building hanging from below, or built above the highway. A view of the river from offices is probably among the best in Minnesota. It will not impair other’s view of the river especially much, and would generate a significant amount of revenue to pay for reconstruction.
An example would be the historic London Bridge, which had houses and stores along the side, encroaching on travelways. There are better ways to combine transportation arteries with development opportunities, and creative design can show the way.

Flying cars coming soon to ten feet above your head

Jalopnik Loves Flying Cars: World’s First Flying Car Enters Production – Jalopnik
The video is not overwhelmingly convincing that this will hit mainstream any time soon.

The Spontaneous City

The Spontaneous City

The Wiktionary (the dictionary counterpart to Wikipedia) says that the word “spontaneous” derives from the late Latin word “spontaneus”, from Latin “sponte” meaning “of one’s free will, voluntarily”. That meaning still holds, but the word has acquired an additional meaning, acting “without planning”. Planning in contrast is “the act of formulating a course of action” or drawing up “a set of intended actions, though which one expects to achieve a goal”. The words are not strictly antonyms, but they are very far from synonyms. To act spontaneously requires there be no specific forethought, to plan imposes structure and intention upon action.
When I was younger I worked in Silver Spring, Maryland at the Maryland-National Capital Park and Planning Commission – Montgomery County Planning Department (MNCPPC-MCPD). While there I worked on a number of plans and policies, most notably the Annual Growth Policy (AGP) which aimed to regulate the pace of development, and by regulating pace differently in different areas, it also affected the sequence of development. The AGP did not intend to affect the ultimate development of an area, that was left for the plan.
There were a number of flaws with the AGP, but one I thought most important was the attempt to pro-actively anticipate the future rather than responding to decisions. The AGP established “staging ceilings” for each area of the county (about 30 or so), the was the maximum number of jobs and housing units permitted in that area, so that public facilities would be adequate. One fundamental difficulty was that the optimal number for one area depended on what actually happened in other areas, which of course was unknown until that development actually occurred. Thus the staging ceilings in one area were conditioned upon ceilings in another area, that may or may not have been exceeded (there were lots of ways ceilings could be exceeded, but if the ceiling were exceeded, the area was placed in moratorium for new development).
This experience, contemporaneous with the fall of Communism, shattered my naive beliefs about planning, and along with reading Hayek’s The Fatal Conceit, it also shattered what I had not thought deeply about in terms of the problems of forecasting. Growing up in the 1980s I had some belief in markets, clearly the economy was doing better in the unregulated Reagan years than in the 1970s. Yet I also understood there were market imperfections, externalities, and public goods that an unregulated market just did not properly account for.
I had grown up in Columbia, Maryland, a highly planned new city from the 1960s, and clearly I was constantly reminded in the promotional literature, it was a better place to live with fewer problems than unplanned sprawling suburbs or the decaying inner city. One of the main critiques of Columbia was its sterility, its lack of life. Things were not out of place there, there were no non-conforming uses.

Could one plan without planning?

The first notion I had while at MNCPPC-MCPD was the idea of just-in-time or dynamic planning. Instead of trying to proactively predict the future, could we just respond to market proposals with a yea or nay (and other feedback). If the proposal met standards, it would go forward, if not, it would be rejected. The standards would not be site specific, but instead be geared toward assessing things public agencies should be concerned about, namely ensuring public facilities remained adequate. I was thinking mainly about replacing the AGP growth management system, rules about zoning and so on were not really in my purview. This was really more like dynamic regulating than dynamic planning.
The difficulty raised with this is that it reduces certainty for private-sector actors, who under the AGP at least knew in advance whether public facilities were adequate. Certainty is not the only value on which a public policy should be judged, I could establish certainty by prohibiting all development, and that would not be good for the private-sector either. Further, developers who have already been approved might like the idea that their competitors cannot go forward because all of the available infrastructure capacity has already been committed.
The second notion came later, while a graduate student at the University of California, Berkeley, as a way to replace zoning. The the role of the public is to establish a vision for the future, and the role of public servants is to facilitate and enable that vision. The vision is not generally site-specific but vague. Development would be judged by whether they moved toward the vision or against it. No plan would be written, no zoning enacted, only the vision would be expressed.
This decreases certainty even more. But it challenges developers to achieve consensus with the neighbors of potential projects.
After teaching a transportation-land use course at the University of Minnesota for a few years, I stumbled upon a third notion. This was to challenge the core tenet that planning actually creates better places.

What does one want from a place?

One thing I want is vibe or vibrant communities. I also want the ability to do what I want when I want. This I will call “spontaneous action”. Spontaneous action requires at least two elements.
The first is the presence of things I want to do. This presence is both spatial and temporal. The thing must be where I want it to be, and it must be open or available when I want to use it.
The second is the ability to reach those things when I want to. I need to have a means of transporting myself conveniently from where I am to where I want to be when I want to go there. There must be both destinations and networks that satisfy action.
There are many locations that have networks, and people who have vehicles, that allow them to move about easily. In any small town or rural community, someone who has a car can easily move about, but there is nowhere to go. These areas have high mobility.
Some places have lots of activity. Cities in general have high density. However because of crowding it may be difficult to move around very much, these places may be congested, limiting the speed and comfort of travel.
In the best places, there are lots of places to go and things to do, and the network is constructed with appropriate differentiation so that are fast links connecting dense places. The net is that even if one can reach things faster than in a small town, because the slow speed is compensated for by the short distance and the relatively high speed links, these areas have high accessibility.
Different people want different things. If we all wanted the same things, life would be pretty boring. Still accessibility is something that many people do want.
Places with higher accessibility allow more spontaneous action than places with lower accessibility. Land prices are higher in places with high accessibility both because of the scarcity of such places and their value.
There is a premium to be paid for “spontaneous action”, an option value that people hold, even if they never go to a show, or a game, or the museum, or the particular specialist shop (the bookstore specializing in gambling books I found in London e.g.), the accessibility gives them the option of engaging in that activity.
(As used here, spontaneous action is limited to what others are willing to allow or accommodate. There are many things for technical or economic reasons I cannot acquire and many activities I cannot engage in because they do not exist).
The opposite of spontaneous action is scheduled action. If I cannot engage in things when I want, I must plan in advance when to do them. This may be because of other people’s constraints, or limitations to the transportation system, or hours of business of the thing I seek. The advantage of a large city is the increased flexibility, the high frequency of transit services, and the increased likelihood of finding a 24-hour store specializing in what you seek (London notwithstanding)

Spontaneous development

Land use planning emerged for a reason, it was a response to the negative features of unplanned, uncontrolled development. Some people did things, like build quarries, that really upset their neighbors. The “nuisance” lawsuit was thought to be insufficient, and quite reactive, would it be possible to proactively avoid this problem? Zoning was one response. Zoning would implement plans, and provide “visions” for individual parcels. It provided certainty at the cost of flexibility. It also capped density in many places, perhaps below where the market density would have been. (It is very difficult to do counter-factual analyses of something like this, and the extent to which zoned density exceeds actual density we can say that the market requirements were lower than the zoning, but when the actual density equals the zoned density, the market desires were probably greater than that permitted, but by how much is impossible to say with certainty).
Zoning is not a requirement of today’s cities, Houston, Texas is often pitched as A city without zoning , though there are contractual covenants and other private equivalents of zoning in many areas of the city. Moreover, the city has numerous other regulations affecting land use.
Spontaneous development would still need to respect property rights and rule of law, though the law would be more limited than found in many places today.

Does planning lead to more or less spontaneous action?

Can we plan and regulate cities to achieve more spontaneous action than an unplanned city?
Presently, that question must remain a question, the question of “can we plan” is very different than “do we plan”.
We can think of a graph with two-axes.
On the x-axis we have degree of spontaneous action, with the zero point marking a totalitarian city under siege with a curfew imposed, and the right point complete freedom to consume whatever the market can produce.
On the y-axis we have degree of spontaneous development, with the zero point marking a pre-planned communist state and the topmost point complete freedom to develop. The question is, what is the shape of the curve? Does spontaneous development enhance or constrain spontaneous action? Is there any relation?
Degree of Spontaneous Development
0——————————— Degree of Spontaneous Action
0 high

Spontaneity in a can

One of the features of modern planning is the attempt to provide vibe and spontaneity in the urban environment. The festival marketplace is a classic example. If only we can create an exciting, but controlled atmosphere, then we will have achieved the best of spontaneously arisen places without their defects. The market for these festival marketplaces has been mixed though. For every success like Baltimore’s Harborplace, there is a failure like Minneapolis’s St. Anthony Main. The very regulation that aims to limit the negative effects minimizes the spontaneity to the point of failure.
Unlike SPAM, vibrant spontaneity does not come in a can, it is not some formulaic easily reproducible phenomenon.


There are numerous interesting examples one could look at.
There are various types of places which involve different types of planning by non-governmental agents:
Event City – Fairs, Festivals, Shows, Conventions, Sports
Enveloped City – Skyways, Subways, and Shopping Malls
Planned City – Columbia
In addition one could compare cities/places that have various degrees of land use control and various degrees of spontaneous action. New York has a high degree of spontaneous action, and probably once had a high degree of spontaneous development (though this was on a pre-specified grid network). Many developing cities still have spontaneous development to the consternation of city officials, though the alternative might be no development at all.
We also need measurements of spontaneous action. Travel and activity surveys tend to ask what was done, but not about what wasn’t done, or how long the activity was planned for. A new type of data gathering instrument is required to fully assess the question. Do people in large cities spend more or less time planning their actions? How far in advance do they plan? (there is some research on this to be sure, but nothing I am aware of allows inter-metropolitan comparisons. We can look at the number of trips made, but that is only a partial indicator, because many trips have substitutes, we need to determine the quality of those trips as well.

Levinson, David (1997) The Limits to Growth Management. Environment and Planning B: Planning and Design 24: 689-707
Levinson, David (2003) The Next America Revisited Journal of Planning Education and Research Summer 2003, Volume 22, Number 4, pp. 329-345.
Hayek, Friedrich (1988) The Fatal Conceit: The Errors of Socialism. The University of Chicago

Point trading

From The Times (via Techdirt) Pensioners take cash and points to keep speeding drivers on the road
“It is the latest ruse on the roads of France: drivers are avoiding disqualification by trading licence points on the internet.
Complete strangers are taking the rap for speeding offences in return for up to €1,500 (£1,000), and police admit they are powerless to intervene. Even pensioners who have not driven for many years are getting in on the act.”
Basically since the speed camera cannot see inside the vehicle, and the violation goes with the driver not the car, people can lie about who was driving. Whoever said the French were insufficiently entrepreneurial?