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 http://nexus.umn.edu/Papers/GrowthManagement.pdf
Levinson, David (2003) The Next America Revisited Journal of Planning Education and Research Summer 2003, Volume 22, Number 4, pp. 329-345. http://nexus.umn.edu/Papers/NextAmerica.pdf
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?

The Elements of Vibe

What is vibe? Vibe is the vitality of street life, the feeling that there is something going on, of being where the action is. Successful places have vibe, dead places don’t. We don’t want vibe everywhere and probably can’t support it. But surely we could have more active places then we do now with a better location of activities.
We drive to places we can walk around, rather than walk around our own neighborhood, unless we happen to live in a place with vibe.
Why do we want to walk around? Because there are multiple things to do: find food, browse books, hear music, entice the intellect, stimulate the senses. This concentration of activities only happens because of the crowds around, and the crowds only gather because of the concentration. More begets more.
These are ‘economies of agglomeration’ as the economists might say or perhaps ‘network effects’. But they allow for the spontaneous walk-in business rather than the planned trip. Many businesses are unlikely to attract spontaneous walk-ins, for instance vacuum cleaner repairs, [I don’t normally walk around with a vacuum cleaner on the hope I will find a repair shop] and thus lose little by not being located in the center of action and save much on rent. Some restaurants are so good, they require a reservation, and thus there is little spill-in traffic. But other businesses, by saving on rent, are foregoing additional business.
Moreover, those businesses are denying potential spillover traffic to their would-be neighbors. It is a calculation that proprietors must do for themselves, but there is a coordination function that a good entrepreneur can serve, matching businesses that attract walk-ins with compatible stores, and maybe subsidizing (lowering the rent for) those that generate more spill-over traffic than they attract.
There are three seeds:
* A concentration of people (customers, though they need not be spending money, that helps)
* A concentration of stuff (suppliers, who need not be selling)
* An environment that encourages people to spend time doing stuff (marketplace)
People concentrate for a variety of reasons – to exploit the material resources of the earth, to have safety in numbers, to find a pool of potential mates, or simply because it is at the intersections of routes between two other places. These intersections (nodes in transportation lingo), create opportunities. In the streetcar era, people might change lines at a node, and those pedestrians would create the streetlife necessary to support new businesses. In the highway era the scale changed, and nodes are the interchanges of freeways. Businesses, and especially shopping malls, take advantage of these points of high accessibility. But the shopping mall is now clearly the destination, not a side-product of a transfer point in the same way street-car corners were.
Some further assertions about human nature:
People like pleasant climates – dry, not too hot, not too cold, clean air, not too loud.
People want to feel safe – they don’t want a car careening out of control disturbing their sidewalk café meal, they don’t want to think they will get run over crossing the street.
People are lazy – they don’t want to walk too far to get where they are going. If they are driving, they want easy convenient parking near their destination. They like to cross the street midblock and don’t want to have to walk to intersections.
People are cheap – they don’t want to pay for that easy convenient parking, they prefer lower to higher prices for the same good.
The last two be summarized by the idea that “People take the path of least resistance�?.
Observing cities around the world with an informed, but casual analysis leads me to assert some rules about the environment that lead to vibrancy.
Buildings on the sidewalk – vibrant areas have buildings that abut sidewalks with not large gaps between the building and the walk. The density of activity is necessarily reduced by space between building and path (and thus other buildings).
Sidewalks on the street – to have vibe, sidewalks must abut the street, or *be* he street in pedestrian only areas. Pedestrian only areas can work, and anyone who says otherwise has other interests at heart. This does not mean that they will work, but given the right environment, people would prefer to shop without having to look out for motorized vehicles.
Streets move slowly – fast streets make pedestrians feel unsafe, and thus reduces the benefits of being on the sidewalk. Ideally streets are moving at pedestrian speed in the pedestrian area. Of course streets leading to the pedestrian area move faster, or people could not get there.
Vehicle space on the street is minimal – wide streets increase the distance pedestrians must walk to reach other activities. Narrow streets give access to more stuff in less time. Hence the reason many enclosed shopping malls work better than many shopping streets is the density of stuff is fairly tight.
Street two way – One way streets may not be inherently problematic, but one-way streets are generally that way to move more vehicle traffic faster through the area, which is the opposite goal of moving pedestrians between buildings within the area.
Opportunities to explore just around the corner – hidden (pleasant) surprises are one of the things that make cities interesting to be in, if I go around this corner what will I discover. The same opportunities do not exist in an enclosed shopping mall, where everything is pre-mapped and tightly controlled, and I know each “block” ends at a parking ramp. Hidden unpleasant surprises however are one of the things that can kill a city, I don’t want to experience dread when I walk down an alley attached to my favorite shopping street.
This set of rules is by no means complete, but rules like these created streetlife in streetcar era places, and they create vibe in the better shopping malls. 

elevators, shafts, and rail privitisation

Did UK’s rail “privatisation” work. Two posts debate the issue:
(1) Globalisation Institute – The reality of rail privatisation in the UK
(2) Transport Blog: Alex Singleton. Communist.
The problem with vertical separation is the tight integration between trains and track (unlike the loose integration between lorries and motorways). For trains, the intelligence is in the track, separating them is much more difficult than in other transport. We would not think of taking elevators and elevator shafts under separate management.
On a side note: The British seem far more willing to throw around terms like “communist” than in the US, where “liberal” is much plausibly damning (and calling someone a communist is beyond The Pale).

Does creativity wither with age?

Does creativity wither with age?
Hypothesis: No, creativity does not wither with age, though for scientists it appears to.
(1) Knowledge stores. Young people have less knowledge, any idea they generate seems new and original. As aging progresses, stores of knowledge increase and apparent insight is attributable to someone else and dismissed.
Cp ~ 1 /K
K – knowledge store
Cp – self-perceived creativity
(2) The idea queue. As one ages, one develops a large number of ideas. Science, however, unlike blogs, requires more than ideas, they must be tested. Once a sufficient number of ideas is generated, the service rate of testing constrains the number of ideas through the bottleneck of publication. New ideas arrive and sit at the back of the queue unless
(a). a queue jumper is installed, or
(b). the queue is a stack – unfortunately, working on only the most recent ideas may be seen as “flighty.”
(3) Advertising. A third related factor facing faculty is the need for “advertising”. A new idea to take root must be beat into the ground. This requires multiple papers, presentations, etc. on essentially the same topic (with of course each paper being an important contribution supporting the whole line of argument, with new empirical evidence, a different model, alternative parameters, related questions). Would that I could say it once and the whole world would hear. Every moment doing something similar is one less moment I could be doing something quite different.
(4) Resistance. The academic system, like all self-preserving systems, is geared away from new ideas. Several factors are at play.
(a) once tenured, the existential pressure (publish or *perish*) is off
(b) publication is easier for minor adaptations and new ideas than for more radical notions (rich ideas get richer).
(c) professional duties require passing on existing ideas (teaching the curriculum) more than professing new ones.
(d) committees/administrivia suck energy from creative people.
(e) money for new faculty is less restricted than others? [I am not sure whether this holds]
(f) older people are more likely to have children, which also suck away time available.
(5) Time budgets. Communication of ideas is inversely proportional to the generation of ideas. A time budget allows you to generate ideas or communicate them, the more you generate, the less time for communication, and vice versa. The more other things one is doing, the fewer the number of ideas generated.
(6) The nature of idea generation may change. Idea generation can be inductive or deductive
(a) For existing problems and solutions … one can parameterize the question and explore the relevant parameterized space.
(b) Alternatively one can borrow / steal / transfer ideas from related disciplines. (Good artists copy, great artists steal.)
One can take an existing problem – formalize it, and then apply scientific method. This is good for “normal science” but is less likely to achieve real breakthroughs. We need to identify new problems, or new hypotheses for existing problems to make important contributions.
Practice ————> Theory
With age, deductive reasoning may become more common and inductive reasoning less so, perhaps because of the "knowledge store" problem discussed above.
(7) Dysfunctions: A major dysfunction with idea generation is the generation of useless or damaging or wrong ideas. The main punishment for this is either wasted time (if it is not published), or shame and humiliation (if one does get published with a wrong idea). Of course many wrong ideas may be necessary to find right ones. However as one advances, the cost of punishment rises, particularly for public wrong ideas. A young person with a dumb idea is quickly forgotten, as there was no reputation to lose, a famous person with a wrong idea loses reputation.
(9) An alternative hypothesis is that creativity does wither with age. Though I don't like this one as much (for obvious reasons, it implies I will be less creative as I get older). A possible explanation is that older people have "hardened" brains, so new connections are harder to establish. Lots of biology may explain why this is so.


From BBC: Connected cars ‘promise safer roads’.
To be valuable, this must work in a mixed environment. Not all cars will have communication devices reporting to them, and even cars with such devices might see them disabled from time-to-time. Communication between cars is fine, but the key to the future of smart cars is the ability to sense the environment independently, and operate in that perceived (rather than reported) environment. Only that can be deployed.
Consider the first year when only a small percent of cars will have the technology. If the system requires all the cars to have the technology, who will pay extra for it? If it requires no other cars, but adds value, people may buy it.

Goofballs and Trainwrecks: This week in London Transport

I come home to London from WCTR to car bombs and people driving into airports (shall we now inspect all cars driving into airports … and then the security line becomes the target, secure areas always have insecure areas outside boundaries and entrances).
Fortunately, this particular cell were not a particularly competent terrorists, so I will refer to them as goofballs. I have yet to see whether they were competent doctors? One hopes the goofballs healed better than they attempted to inflict harm.
Later in the week, a train derails:
Metronet warned in May over derailment danger. A number of passengers had panic attacks, thinking it was another terrorist attack, coming almost 2 years after 7.7 and days after the Piccadilly smoking car.
The greater harm done by terrorists (even the goofballs) is not the physical damage, but the terror (which gives this -ism its name), and people living in terror. This culture of fear is amplified by news and free flow of information.
The book Paradox of Choice by Barry Schwartz talks about the curse of abundance, we have too many options and by extension too much information. This repudiates the economists argument of “non-satiation”, required for well-behaved utility functions.
Of course many bad things happen in the world, but when personal tragedy strikes people I don’t know, and will never know, do I really need to know and am I better off if I know?
Cars hurtling on fire toward airport entrances and dud-car bombs might rise to be slightly larger than personal tragedy, but not too much larger. Scarcity makes events like this unusual, and therefore newsworthy, but unlike “dog bites man” wherein the dog was after the man rather than the news-story, getting attention from the news and causing fear is exactly the terrorist aim.
The appropriate response would be to note it, arrest the goofballs, and move-on, rather than obsessing and changing our ways and continuously reminding ourselves of the goofball agenda, and thereby empowering it. Attention is the ransom demanded by terrorists, and we don’t pay ransom for fear of encouraging kidnapping, we should not pay attention for fear of encouraging more random acts of terrorism.