Credibility vs. Expertise

I recently turned down a research project from a private transportation company.

They approached us with an opportunity to do a moderately interesting analysis (nothing earth shattering, but would make a decent MS Thesis). We proposed in response, negotiated, and more or less agreed to the terms of work. As we were entering contracting stage, they wanted approval over what we could publish from the research (not simply being informed of what we were going to publish, and given the opportunity to provide comments, which is fine and simple courtesy, not simple delay, but approval, even after the contract closed). While this is generally unenforceable, we cannot agree to these kinds of terms and maintain our integrity.

I understand why they want this. We might say something that is not in the company’s interest. If what we say agrees with what they want said, they would approve, if not, they would squash it. This creates a positive results bias in a way.

I belong to a research university not a consultancy. The reason we engage in research is to discover truth. We then make our findings public to add to the store of human knowledge. Further, students need to be able to publish their MS Thesis, both to prove they wrote them, and for their own careers, leave aside adding to human knowledge. I am not sure how people in defense and medicine do research, but transportation is traditionally public sector.

We are, I think, cheaper than consultants in general, in part because we have this subsidized student labor, who forego salary in exchange for education, part of which is a research experience, they payoff of which is downstream publication if it is good enough. Students should not be exploited (or let themselves be exploited) this way, where the outcome of their research depends on whether the funder likes the results.

My conclusion is that the private firm was in fact trying to buy our credibility (if the “objective experts” at the University of Minnesota say something good, publicize, otherwise bury) rather than our expertise. While I recognize these are jointly produced — our expertise, as demonstrated by publication in peer reviewed journals produces credibility; credibility expands opportunities to obtain expertise — it would not take too many of these contracts before that credibility would be destroyed.

Now, I understand other organizations who fund us in a way buy our credibility too. And if they like what we say, they issue a press release, and if they don’t they just ignore it, and leave us to the many readers of Transportation Research part Z. It gets published, it just doesn’t get as widely distributed. That’s fine. No one promised us free marketing for the research.

And I also understand that we are not a blank slate, we are more likely to attract some funders than others because of what we are expected to say based on past experience. There is self-selection all around. That too is the nature of the world. I can still publish, they can still choose to publicize or not. But I am not pre-committing to an outcome, and am not changing my analysis based on the desire to be funded.

The consequence of turning down this contract is that perhaps one less student got funded to do an MS Thesis in Civil Engineering at the University of Minnesota, and instead went to the next highest ranked university in the field (displacing the weakest student who was admitted there). Maybe this firm found another university to do their bidding. Maybe the displaced student went there. I don’t know.

On Why Bike Lanes Might Appear Underutilized

EUMobilityWeek1We hear complaints that bike lanes are underutilized.

This might be true, or it might appear to be true and not be true.

Let’s think about the traffic physics of this.

Elements of Access: Transport Planning for Engineers, Transport Engineering for Planners. By David M. Levinson, Wes Marshall, Kay Axhausen.
Elements of Access: Transport Planning for Engineers, Transport Engineering for Planners. By David M. Levinson, Wes Marshall, Kay Axhausen.

Imagine there is a lane of traffic full of cars, say a flow (Q) of 500 vehicles per hour, going very slowly, an average speed (V) say 5 km/h because of congestion, traffic signals, unloading trucks, and the like. The lane will appear full, because the density is high. Density (K) is vehicles per km, and the relationship between flow, density, and speed is given by Q=KV or K=Q/V. In this example, the density is 100 vehicles per km, or about  10 vehicles every 100 m, or 10 m between vehicles, which is a pretty high density. Not quite jam density (minimum vehicle spacing, maximum vehicles per km, on the order of 150), but close.

Imagine there is a parallel lane for bicycles. They are traveling at 20 km/h. The spacing is one bicycle every 40 m, or a density of 25 bicycles per km. Yet the flow is an identical 500 vehicles per hour (Q=KV). The lane looks one fourth as full (even less, because bicycles take up much less space than cars), but serves just as many vehicles as the crowded lane.

Now of course the bike lane is narrower than the car lane, so if we were to look at bicycles per square meter, accounting for a car lane of 3 m (typically 3.65m, but narrower in cities) and a bike lane of 1.5 m, we only need a density of one bicycle every 80 m to get the same flux (flux is flow accounting for the width of the lanes and vehicles). One bicycle every 80 m is about 1 bicyclist per block at a given time. In contrast that congested  lane of cars has at least 8 vehicles in it for the same length block.

(I realize I should evaluate person throughput rather than vehicle throughput. For illustration, I am assuming 1 person per motor vehicle, which is a bit pessimistic, in practice it is closer to 1.1 for work trips and 1.5 all day).

Now, I am not saying the bike lane has 500 bicyclists per bike lane per hour (or the road has 500 vehicles per lane per hour). Most have fewer. Your kilometerage may vary.  It doesn’t have to. The alternative use of the lane may have been storing cars. They have a speed of zero and a flow of 0, and a pretty high density (roughly 150 vehicles/km) for being unproductive.

Furthermore performance in terms of flow (or flux) isn’t the only question at hand. Safety is important too, and bike lanes are typically safer for bicyclists than riding in traffic, and sure feel safer.

Autonomous vehicles and the shortest path

We have given a number of reasons that autonomous vehicles will reduce congestion.

“In particular, vehicle automation, once it gets critical mass, should greatly increase road capacity, both because of shorter following distances and because of narrower lanes. New, narrow vehicle forms designed for a single passenger (which is how most cars are used) will become more widespread with automation, as safety fears diminish, and will also increase person throughput.”

Example of Route Detecting and Comparison of Alternative Paths

I have thought of one more reason autonomous vehicles will reduce traffic congestion. Currently most drivers do not take the shortest path (though we don’t really know why that is so, we have speculations). If we take humans out of the navigation decision, cars will be more likely to find the shortest path. This may not be system optimal, but will be a significant improvement over current routing decisions.

Not only should we not let people drive, we probably shouldn’t let them route themselves if we want an efficient system.

Lean on me (or why blogging matters, especially for faculty).

“Nice project [career, job] there son, shame if something happened to it” …

That is the implied message I got a bit a year ago from an intermediary passing along comments from a local appointed official serving other local appointed officials unhappy with comments I made in a newspaper article inspired by a post on this blog. (The local appointed official came out smelling like roses in this article, the local officials he worked for did not). Of course it wasn’t put in quite those words, and they don’t even fund me. (The lead appointed official this appointed official worked for was subsequently not renewed).57411306

I have heard similar comments from others who blog and work in a relatively small network within a particular industry, and fears of the same from those who would like to blog but won’t. This is a problem. The people who know the field best, those who work on it day in and day out, are afraid to speak.

Dude, I am a professor. I have tenure. I have a salary. The only people you can hurt (unless you can actually get me fired for free speech, which I doubt – I imagine the University of Minnesota faculty would have something to say), are graduate students, who won’t get funding if you cut off that avenue.

My job, and the reason I have tenure, are to say things that might not be politically “savvy”. This is why I am hired by the University and why the University has a tenure system, and why it receives a modicum of funding from the People of Minnesota.

If I were to only say things that were “Rah, Minnesota” and pat ourselves on the back (1) No one would read this blog*, (2) No change would ever occur, (3) I would be derelict in my duties.

There are of course plenty of people paid to say things like “Rah, Minnesota”. We build whole stadiums (we build fleets of stadiums in fact, and we have the newest fleet of stadia of any City in North America) to pat ourselves on the back and feel the joy of the one-ness of life in the barren wilderness of the North, the provincial capital of the only region on planet Earth not getting warmer due to “Global Warming”.

If things were perfect, and I were just a curmudgeon who did not acknowledge the perfection of our society, perhaps I should be ignored. [Does a perfect society tolerate or contain a curmudgeon? ] I think evidence however is that we live in a less than perfect society, and while we may disagree on the nature of the imperfection or its solution, few argue the Panglossian case. The causes of the imperfection are not just the symptoms, but the underlying structures that produce the symptoms. This includes things like Governance. This is not simply a technology problem (in fact, much of it is not a technology problem – though there may be technologies that can route around the political problems).

Now the “savvy” professor who only says the right things to patrons may get more money, or more promotions into administration (which obviously many of us are capable of (and most of us think we could do a better job than those in those administrative positions – whether or not that’s true), but who really wants to deal with more bureaucratic processes than we already do). In a field which is sufficiently technical, this may be fine. In pure sciences like chemistry, one assumes that discovering a new element ruffles few political feathers (though undoubtedly there are all sorts of intra-chemistry politics). Yet even seemingly “technical” breakthroughs like fracking have many social consequences, just look at the price of fuel.

Transportation is a socio-technical system. A savvy professor who does not touch the “socio” aspects of the systems, will leave no mark upon the social systems of the world that govern the technology.  Tenured faculty have an obligation to  speak truth to power, even if it is outside their nominal domain.

  • There are lots of boring institutional websites and blogs. I won’t name and shame.

Property vs. Liberty

Some people place property rights above human rights, and want the government to defend with force their right to discriminate (against group X) in their own business. The right to discriminate on the basis of race (or worse, the obligation to discriminate) with the protection of the state, which has a monopoly on the “legitimate” use of force was made illegal in the US some 50 years ago due to the success of the Civil Rights Movement.*

While property arrangements are generally accepted, they are not themselves the product of pure merit, and should not be treated as sacrosanct. How did any particular distribution of property come to be? Is that the most just distribution of property? And why is that right privileged above all else? There is a strong truism that, as Balzac said “The secret of great fortunes without apparent cause is a crime forgotten, for it was properly done.” More colloquially, due to Puzo, “Behind every great fortune is a great crime.” Certainly hard work coupled with great crime is more productive than crime alone. Similarly good luck, hard work, inherent ability, and great crime is best of all. As popular as she may be, who exactly elected the Queen?* Buckminster Fuller dubbed the class which established many great fortunes during the pre-Industrial seatrading era “the Great Pirates” in Operating Manual for Spaceship Earth.

The government (with its monopoly of force earned by force) grants monopolies all the time, often for very practical reasons, ranging from natural monopoly to patents to encourage the useful arts, to ownership of property (which is a very localized spatial monopoly). But they are monopolies none the less, and thus move us away from an idealized atomistic perfectly competitive economy which is the basis for pure libertarian reasoning about rights to trade with whomever, whenever you want. So if the assumptions on which the logic are based are invalid, the conclusions do not necessarily apply.

From an efficiency perspective there is great value in stable property relations and encouraging hard work. If you thought your wealth would constantly be confiscated and redistributed, you would be very tempted not to produce anything. That after all is the libertarian argument against high tax rates, estate taxes, and so on, empirically corroborated from a reading of history in communist countries, though derivable from first principles about human behavior.

Equality vs. Equity: Source This is really about Equality of Opportunity (everyone is given the same box) vs. Equality of Outcome (everyone can see the game).

From a social perspective, while we perhaps cannot do much to control inherent ability, and we discourage great crime, we can create the conditions for good luck (tending towards equality of opportunity: a minimum level of food, health, knowledge, political access, and so on) and reward hard work. Yet there is a tension between the two. The resources necessary to ensure equality of opportunity somewhat diminish the reward for hard work. This is the nature of the system. The system however can raise more resources with less disincentive to work by how the tax code works. What is taxed: work or land, consumption or production?

Today, the initial distribution of property (and talents) people are born with is far from equal. And people with wealth are able to channel some of their wealth to persuade (via campaign contributions, revolving doors, and straight-out bribery) the state to preserve their wealth (through crony capitalism, special tax breaks, and other means), while using the commons (e.g. the air, the atmosphere, the ocean) as a dumping ground for their pollution, and exploiting the unregulated commons for private gain. This is all selfishly rational, homo economicus behavior. We are not surprised by it.

Some groups are further able to use police powers to control other groups. While this is far from rational in an economic sense, it is rational in a political sense, keeping the “in group” in power and keeping the “out group” down.

But just because we expect hypocrisy in the name of preserving wealth, doesn’t mean we should accept it. The rules of the game may be tolerable (not perfect, but good enough) if everyone starts at the same place, but are far from acceptable when some are kept down by the instruments of the state while others are promoted (at least in a relative sense, if only by not being kept down).

The American founders were wise enough establish a set of principles that, though they didn’t live up to them themselves, have steadily increased democracy. Instead of just propertied white men, almost everyone can vote (children, convicts and undocumented immigrants among the excluded classes). Instead of slavery, we now have defined rights more broadly.

We should seek a society where everyone can fairly trade with whomever they wish, without interference. That requires property rights. Such a system is inherently unfair though that is unpersuasive to those who care solely about efficiency. It is also politically unstable (and thus fails in the long-run) without an underlying fairness in the initial distribution. And the initial distribution will be inherently unfair each generation without some periodic corrections. (And likely get unfairer over time in absence of remedies.) Abilities are not randomly distributed; neither are wealth and opportunity when some can benefit from the work of their ancestors, and others cannot. If we ancestors are not permitted to provide benefits to our descendants, that greatly diminishes our incentives to create, produce, and save/invest.

Politics in a democratic republic is about balancing these interests. Factions will favor one over the other – pushing more toward efficiency or more toward equity. That is what we want if we believe there is a collective wisdom.  But if a faction or party tells you only one side of this see-saw matters (either growth at the expense of any redistribution, or redistribution at the expense of efficiency), they are rigid ideologues not to be trusted.


  • Montgomery Bus Lines, the public transit firm serving Montgomery, Alabama, in 1956 was owned by National City Lines, a private firm at the time of the famous boycott. Martin Luther King and others were jailed for boycotting, conspiring to interfere with a business, which had a government-granted monopoly. Today even most Alabamans probably recognize the wrongness of the situation.
  • Kings and Queens were once elected. E.g. Royal Elections in Poland. The current Queen of England obviously was not elected.


Mobile telecommunications altering behavior, mode choice

The rise of Graphic of words related to mobile activitymobile technology (such as 6G phones and in-vehicle Wi-Fi) is changing the way people spend their travel time and even altering their travel choices, and these changes will continue as technologies become more advanced and autonomous vehicle technology matures. Experts predict that as the increasing use of telecommunications makes travel time more useful, it will increase people’s willingness to travel.

In a recent report, Associate Professor Yingling Fan of the Humphrey School of Public Affairs explores the current understanding of how technology in motion will shape the future of travel and transportation.

Research has shown that rail and bus passengers use their travel time in a variety of ways, with roughly 55 percent of rail passengers and 40 percent of bus passengers engaging with technology. A number of factors affect how travel time is used, including journey purpose and direction of travel, age, gender and class, trip duration, and environmental factors such as seating availability. Recent studies have also suggested that telecommunications could significantly influence mode choice.

“Broadband access on public transportation systems has been shown to increase ridership and encourage people to shift from cars to public transit,” Fan says. “However, it plays less of a role than more important factors such as total travel time and service reliability.”

Her research also used data and activity categories from the American Time Use Survey to identify new activities that could occur “in motion” as self-driving vehicle technology matures. These include a limited set of personal-care activities, a limited set of child-care activities, eating and drinking, tobacco and drug use, and participation in religious activities. Fan’s analysis shows that the average person spends about two hours on these activity types daily.

New technologies could have several important impacts on our transportation future, Fan says. The ability to use information and telecommunication devices may continue to help attract “choice” riders (those who are able to drive and afford a vehicle, but choose transit) to transit. Self-driving cars may get larger in size to meet a growing demand for more space for increased activity options and improved comfort levels.

“In addition, travel patterns may change as a result of new technologies,” Fan says. “People may start traveling more as the number and usefulness of activities that can be conducted while traveling increases—they may be more inclined to replace hub-and-spoke trips toward a central point with circular trips chained together. The saved travel time and increased utility of travel are likely to encourage visits to more distant but more attractive destinations.”

Finally, mobile technology and self-driving cars are likely to have fundamental impacts—which may not be positive—on our society. These include transforming the urban form, making people more likely to choose housing location based on their preferences rather than spatial accessibility, and creating fewer but larger business centers.

The study was sponsored by the Minnesota Department of Transportation (MnDOT) and the Minnesota Local Road Research Board. “This research suggests that communications technologies will continue to impact our lives even more profoundly in the future,” says Ken Buckeye, program manager in MnDOT’s Office of Financial Management. “Where we live and work and our modal choices will be influenced strongly by our ability to stay connected in the manner we choose. This research has important implications for how we plan, develop, and operate our transportation networks and systems.”

Fan’s research is part of a multi-pronged study that analyzed the technological shifts altering surface transportation and the implications for Minnesota. Other contributors included principal investigator David Levinson, professor in the Department of Civil, Environmental, and Geo- Engineering (CEGE); Adam Boies, CEGE assistant professor; and Jason Cao, associate professor, Humphrey School of Public Affairs. Their high-level white papers are compiled in a final report: The Transportation Futures Project: Planning for Technology Change. Future issues of Catalyst will share findings from other chapters.

Related Links

Follow the Red Brick Road |

This blog is about streets and yet we rarely talk about pavements, the road surface itself. The most common materials are bituminous asphalt and concrete, with asphalt more common on low volume local roads and concrete on higher volume freeways. The general reputation is that concrete is stronger and longer lasting but more expensive and more difficult to construct and takes longer to set.

At St. Anthony Main, Minneapolis, the Street is Brick and the Path is Asphalt.
At St. Anthony Main, Minneapolis, the Street is Brick and the Path is Asphalt.

For a brief window in the late 2000s, concrete actually had a price advantage, which explains the surface for the Marq/2 project in Minneapolis. They have other properties and claims made about them. For details on the pavement wars see and (seriously, visit their sites, then come back (better yet, visit their sites from 10 or 12 years ago at (concrete) (asphalt)). Grammatically, if there were only two choices, the concrete folks would be more accurate. However there are more than two choices.

Plank Path at Mill City Museum
Plank Path at Mill City Museum

A third choice is plank roads. These were once common (in the 1840s and 1850s) when forests were still virgin and it was an improvement over dirt, and more cost effective, were it to last. Sadly it did not last. To recall the days of plank roads the Mill City Museum had a plank section installed just outside on West River parkway. Sadly recalling the earlier experience with plank roads, it too rotted before its time, and the other disadvantages (rough surface compared to asphalt) led to it being pulled out on the auto path, though it remains for the bike/walk path.

Woonerf in Delft
Woonerf in Delft

A fourth choice is brick. Fans of the Woonerf, as I have been since reading Streets Ahead, know that many neighborhood streets in the Netherlands have either retained or been restored to a brick or cobblestone surface. This encourages vehicles to slow down and connects the walking, playing, parking, and driving surfaces into one. There are many designs.

But this is Minnesota, we can’t have brick-clad Woonerf here, can we?

Yes, yes we can. Once our roads were brick too. The vernacular design differs with the local Midwest environment, but the underlying logic remains the same.

In many places, the asphalt is simply laid over the brick. (How many, I don’t think anyone knows, as the records, if they remain, are on paper in boxes at an archive.) In some places they have been uncovered. Some examples from St. Paul are below. In some places, like some streets and alleys in the Minneapolis Warehouse District, they were never covered.

Berkeley Avenue, St. Paul (via Google Earth)
Berkeley Avenue, Saint Paul (via Google Earth)
Pillsbury Street, Saint Paul (via Google Earth)
Pillsbury Street, Saint Paul (via Google Earth)

While snow and ice are harder to clear from brick than say asphalt, that too is a traffic calming measure. And there is no requirement that on residential streets snow be plowed to the surface. A compacted snow pack over residential streets will help preserve the pavement compared to scraping them with metal blades.

The merits of respective building materials can be argued, but eventually, about the time we have flying cars and real hoverboards, the more attractive brick will again dominate asphalt and concrete for residential and shopping streets. In the meantime, we can prepare for that day and try to resurface and uncover more and different road materials to help create better looking  neighborhoods and living streets for people.



Cross-posted at

Hillary Clinton’s Infrastructure Plan

Likely future President Hillary Clinton released her infrastructure plan (PDF version) back in November, but I am just paying attention to it now. This is far more detailed than many Presidential plans and suggests someone who is in the field (though more likely an advocate or lobbyist rather than an academic) drafted it for her. Notably it is infrastructure, not just transportation, though it focuses on transport, it includes energy, water, and telecommunications. While transportation is a settled issue for the first few years given the recent passage of surface transportation reauthorization, this document still will set the agenda for the next re-up.

It is more or less the current agenda, but some key points:

  • Increase federal infrastructure investment by $275B over 5 years, paid for with business tax reform, not user fees, because???? [Not that there should or should not be business tax reform, but why should that revenue go to transport rather than the general fund. Why should general fund revenue support transport when user fees are straightforward? One can always frame it as a wholesale tax on oil companies to avoid the “gas tax” moniker. I recognize it is still too soon for road pricing, but something about how electric vehicles would contribute would be nice. Also the plan is not clear on why this is a federal rather than state responsibility.]
  • Reauthorize “Build America Bonds”, which are probably a better mechanism than municipal bonds.
  • Create a national infrastructure bank which is almost a real bank. In principle this is good, though the devil as always is in the details. There is still a lot of vagueness in the proposal (like what’s in it for the bank with regards to loan guarantees, i.e. how does the bank recover its guarantees), but much of the language, like selecting projects based on merit, and no discussion about “grants” is important.

At any rate, I was pleased to see our Fix it First report referenced, even if not really adopted. Hopefully it moved the dial a little bit on discussions in Washington.

The Value of Trail Access on Home Purchases

Recently Published:2013-07-15 at 12-20-03



Many cities, through public dialogues, community initiatives and other land use and transportation policies, are striving to enhance their ‘livability’. While ‘livability’ is a relatively ambiguous term, there is emerging consensus on the following: the ease by which residents can travel by foot or bicycle represents a critical component of this goal. Communities with well-developed non-motorized infrastructure, in the form of sidewalks, bicycle paths, or compact and mixed land uses, are hypothesized to be more ‘livable’ than those without. This argument is often relied upon by advocates of bicycle paths or sidewalks. If livability is cherished among residents, and one important component of livability includes bicycle paths, then it follows that living close to bicycle paths should be capitalized into home prices. Documenting this relationship would provide good news for advocates who often seek ways of monetizing the value of these public goods; bicycle facilities are non-market goods, making it difficult to attach an economic value to them.