Introduction to Transportation Engineering – Decision Making

I plan to “flip” my Introduction to Transportation Engineering Course, i.e. record my lectures and use class time for more interactive projects (like actually building a model). I am going to use the next few weeks of this blog to feature draft lectures (or lecture segments) from the course. The risk is the “lectures” without the interactivity that is normally there, are dryer. The advantage is, without the interactivity, they are much shorter. Further, students can review complicated bits, and can focus on watching rather than note-taking.

Feedback appreciated.

CE3201 P1 02 DecisionMaking

Ice, Ice Lately

So we have survived yet another winter, this with uncountable numbers of days below 0 degrees F. We are now in the early days of meteorological Spring, where the daytime temperatures are above freezing, but the nighttime temperatures fall below that magic number. This means yesterday afternoon’s thin puddles of waters and rivers of runoff are this morning’s thin sheets of ice.

Ice formation on Franklin Avenue sidewalk as a result of street snow clearance
Ice formation on Franklin Avenue sidewalk as a result of street snow clearance

Large sheets of ice are of course bad for cars, which if they cannot control their ton or two of hardware with their four points of contact on the road risk spinning out.

But even small sheets of ice are perilous for pedestrians, with far less force than two tons applied at only two points of contact on the sidewalk.

Further conditions for pedestrians are worse as roads have been actively cleared all winter. Where did that snow go? Well the Boulevards between the road and the sidewalk, and sometimes the sidewalk itself.

Snow "removal" at Franklin Avenue/East River Road/27th Avenue blocks the sidewalk
Snow “removal” at Franklin Avenue/East River Road/27th Avenue blocks the sidewalk

Even further, roads are wide and therefore get more direct sunlight, while the sidewalks are often shaded, and thus cooler, and thus have a prolonged freeze-thaw cycle.

Moreover, sidewalks are generally in as bad or worse condition as roads (prove me wrong with your sophisticated sidewalk monitoring system data). Not just cracks and spalling of concrete, but unlevelness, settling, and so on, all of which are great places for water to accumulate.

Finally sidewalks often  have very steep snowbanks on both sides, caused both by shoveling show from the sidewalk and plowing it from the street, which continuously melts in this period of the season in the day, and freezes in the afternoon.

I have complained and suggested solutions in the past

(in fact a year ago). I am not (yet) suggesting we don’t plow the roads. However if we had not plowed the roads, the sidewalks and the boulevards would all be mostly clear by now.

Twin Cities Rapid Transit, Southwest LRT, and Prospect Theory |

Cross-posted from Twin Cities Rapid Transit, Southwest LRT, and Prospect Theory

Twin Cities Rapid Transit, Southwest LRT, and Prospect Theory

Como-Harriet line - a vestige of Twin Cities Rapid Transit (photo by author)

  While there is clearly some dispute as to the importance of a national conspiracy in the shift from streetcars to transit, one should not dismiss the existence of criminals in the streetcar companies of the era (like the rail era before them). A marked example is in the Twin Cities of Minneapolis and St. Paul, Minnesota. The streetcar lines in the Twin Cities were built by Tom Lowry in the nineteenth and early twentieth centuries, and like many cities were aimed at large part in land development. For the period between 1925 and 1948, fares held steady at $0.10, leading to capital shortfalls. The Twin Cities lines were publicly traded and most shareholders were non-local. The conversion from streetcars to buses took place after a series of events helped drain the company of even more resources. In 1949, Charles Green undertook a hostile takeover. He asked for a fare hike, fired 25 percent of the workforce, and canceled capital investment. He was employing a traditional “cash cow” model, wherein new owners milked the system of resources to pay for its own takeover. A strange turn took place when Isadore Blumenfeld, a.k.a. Kid Cann (rumored to be a gangster and murderer) and Fred Osanna (known to be a lawyer) tried to take the system from Green. The State Railway Commission made an investigation of bribery, embezzlement, kickbacks, and death threats. Osanna and company did successfully takeover the Twin Cities Rapid Transit in 1951, and sold off the streetcars and many of the rails. It is reported that the vehicles are still running in New Jersey and in Mexico City, though while the shells may still operate, whether the mechanics in the vehicles do is unclear. Osanna claimed “the fastest and most massive streetcar-to-bus conversion ever undertaken in any major US city.” However, Osanna wound up in jail for fraud. The system was subsequently sold to Carl Pohlad (later owner of the Minnesota Twins), and was eventually sold to the public Metropolitan Transit Commission in 1970 for $7.9 million.

Linden Hills Station (photo by author)

Though streetcars were clearly on the decline everywhere, this loss is felt deeply in the Twin Cities region. Losses (of things we want) are always felt more than gains. Having the streetcars did not make Twin Citians as happy as losing the streetcars made them unhappy. This observation connects with Prospect Theory of Kahneman and Tversky, and helps explain why change is so difficult.

We are loss averse. Even today, people who were not born here or then are outraged by the inevitable change that took place. I believe loss aversion can be rational as a signaling mechanism. If you believe I will be “irrationally” upset at losses when you take something from me, you will be less likely to take it. You will also over-compensate me if you do take it so that I will feel that I have been properly compensated.

Streetcar interior view (photo by author)

We in the Twin Cities see this playing out in the Southwest corridor, where supposedly a bike lane, an LRT and a freight line cannot fit in the same corridor at grade, and all sorts of irrational work-arounds are proposed. [Matt Steele argues you only need to single track the LRT, and my belief is they could run the occasional freight and frequent passenger trains on the same track or buy out the freight railroad if they wanted too.] The loss here is not the loss of the transit system, but the loss of the quiet associated with the lack of a transit system in Kenilworth, vs. the loss of a bike path, vs. the feared loss of safety associated with a re-routed freight line in St. Louis Park. Instead of solving the problem, there are people who seem to enjoy admiring the problem, as if it were a piece in the sculpture garden.


Historical section adapted from Garrison, W and Levinson, D (2014) The Transportation Experience: Second Edition. Oxford University Press.

Are you down with DST?

I am in the STRIB talking Time, Daylight Saving Time in an article by Kim Ode.

Or, we could just get up sooner

David Levinson, a professor of civil engineering at the University of Minnesota, has studied the effects of daylight saving time from a traffic safety standpoint, finding the shift makes driving no more dangerous than at any other time. But he also views DST through sociological and economic lenses.

Energy savings used to be the primary reason, he said, with the logic that if it stayed sunlit later, people wouldn’t turn on their lights.

“My own view is that people should get up earlier,” Levinson added, not unreasonably.

Levinson concurred with the economic value of DST, noting that merchants believe that the longer it remains daylight, the more likely people will leave their homes to shop.

“The question is: How much benefit can there be? People are going to buy only as many groceries as they’re going to buy. How much is new business entirely because it’s still daylight?”

That may be impossible to determine, partly because at this time of year the days are getting longer in addition to shifting an hour. Where the Twin Cities have just under eight hours of daylight on Dec. 21, we’ll have a little more than 12 hours on March 21 and a whopping 15 ½ on June 21.

Today, about 70 countries use daylight saving time to some extent. And, like it or not, the eastern time zone — whether on DST or EST — makes everyone jump.

Central time zone residents are used to starting their days earlier if they’re dealing with the East Coast.

Our research is here.

Minneapolis-St. Paul is No. 16 on the list of America’s worst traffic cities | Star-Tribune

I was interviewed by Mary Lynn Smith of the Star Tribune for the annual INRIX congestion report article:
Minneapolis-St. Paul is No. 16 on the list of America’s worst traffic cities

Depending on the methodology, rankings put the Twin Cities between the 13th- and 16th-largest U.S. metro area, said David Levinson, a civil engineering professor at the University of Minnesota. “The fact that we’re ranked 16th in congestion seems about right,” he said.

Levinson said demographic trends are helping to mitigate road congestion.

“Travel times are declining in the U.S.,” he said. “People are aging. Old people don’t travel as much, and young people don’t travel as much as what young people used to. Fewer kids own cars. The big picture is that that the total amount of travel peaked in the U.S. a few years ago and it’s been declining ever since. We have some ups and downs during any given year depending on the price of the gas and whether the economy is doing a little bit better or not. Certainly [congestion is] more than in 2009 during the depths of the recession.”

Levinson and others are quick to point out that Twin Cities drivers could be dealing with much worse.

In Los Angeles, home to the nation’s most-congested roads, drivers spent 64 hours sitting in traffic, an increase of five hours from the previous year, according to the INRIX study. In Honolulu, the nation’s second-worst city for traffic, drivers sat behind the wheel 60 extra hours last year, while in No. 3 San Francisco it was 56 hours.

And, Levinson points out, there’s more good news for the Twin Cities. The average speed of travel in the metro area is the fifth-highest in the country.

“You sit in traffic at a particular bottleneck, but then when you’re moving on the freeway, you’re driving at 55 mph,’’ he said. “And when you’re driving on arterials, you’re driving at 45 mph, and that’s better than most metro cities.”

Transit Revolution or a Streetcar to Heck? | The Theater of Public Policy

I am scheduled to appear at The Theater of Public Policy where they will be improv-ing Transit Revolution or a Streetcar to Heck?

The University of Minnesota’s resident civil engineering guru is known around the world as The Transportationist. Professor Levinson will join us to talk about the Twin Cities, traffic, streetcars, and why we don’t yet have hover bikes?

Doors at 6:00 – Show at 7:00

Tickets: $10 at the door OR $7 in advance, or $7 at the door with student I.D., kids under 12, or with a Fringe Button.

Buy Tickets here!

  • Monday, April 7, 2014
  • 7:00pm – 8:00pm
  • Bryant Lake Bowl (map)

  • 810 W Lake St

  • Minneapolis, MN 55408

Women work closer to home

Shomik  Mehndiratta and Tatiana Peralta Quiros from the World Bank write about Buenos Aires:
“[M]en and women’s average commuting times may be roughly the same, but men actually travel at significantly faster speeds and, as a consequence, cover larger distances. In general, trips made by women, particularly women with children were made at significantly lower travel speeds. (see table below: women with children, for instance, travel an average distance of 7.92km at an average speed of 9.98km/hr, as opposed to an average distance of 9.96km for men with children, which translates into a speed of 12.27km/hr).

Table 1
: Travel times, distances and speeds for work trips for men and women.
Work Trips. ENMODO 2009. Expanded Survey
Average Time (min) Average Distance (km) Average Speed (km/hr)
Women without Children 45.3 7.50 9.92
Men without Children 43.3 8.67 12.01
Women with Children 47.7 7.92 9.98
Men with Children 48.7 9.96 12.27

How can we explain those differences? Our hypothesis is that women’s travel choices are limited in part by household maintenance activities, which force them to rely on comparatively slower modes: the survey finds that women walk more than men and take buses, while men are using cars and trains more.

If women are indeed constrained to smaller commutes, it also means they have access to fewer employment opportunities – with inevitable consequences on their wage rates and related labor market outcomes. The map below highlights the stark contrast in job accessibility between men and women in the Buenos Aires Metropolitan Area: in parts of the city, men with children have access to over 80% more jobs than their female counterparts.”



‘Lexus lanes’ and the price of saving time | Marketplace

I was interviewed on Marketplace (by American Public Media) about ‘Lexus lanes’ and the price of saving time (this is drawn from the same interview as last week’s article).

Part of the problem appears to be a phenomenon documented on Minnesota’s MnPASS system, after which Florida’s I-95 Express plan is modeled. Engineers found that, up to a point, drivers are actually drawn to higher tolls.

“And that’s surprising,” said David Levinson a professor of civil engineering at University of Minnesota and a study author. “Our expectation was that when we raised the price, that fewer people would consume the good … which is what you typically find.”

He says you don’t normally think about driving on high-occupancy toll lanes as a prestige good, where people perceive more value as the price goes up.

On the other hand, Levinson says, maybe there is a real value. “So if you’re a ‘type-A’ person you might get some sort of psychological benefit from passing 20 other cars on your way to work. Even if by passing 20 cars you’ve only saved yourself a minute or two, you’re ahead in the race, so as a positional good you think it’s better.”

And for the record, express lanes may or may not be “better” as the price goes up. Dynamic tolling changes to ensure free-flowing traffic in the express lanes — it has nothing to do with what’s going on in the not-so-express lanes.

The paper is here: HOT or Not: Driver Elasticity to Price on the MnPASS HOT Lanes.

The Road Ahead: County Transportation Funding and Financing

There is a nice interactive by the National Association of Counties (by my former co-author Emilia Istrate and others): The Road Ahead which maps the variety of financing issues facing local governments in the US.

The Road Ahead
The Road Ahead

There is a huge variety of organization across the United States. The page notes:

The interactive provides individualized PDF profiles for 43 states where counties have authority over roads and/or bridges. Counties in four states (Delaware, North Carolina, Vermont and West Virginia) do not have authority over both roads and bridges. New Hampshire counties do not own roads and only one county (Belknap County) owns a bridge. Connecticut and Rhode Island do not have county governments and are not included in the study. They are marked in gray on the map.

So why do we need 3 or even 2 levels of government managing roads when some states can do with one? [See Jurisdictional Overload]. Should this be government owned (or executive branch controlled) at all when other utilities are cooperatively or privately managed and publicly regulated? In this era of declining demand for travel, it is seriously time to rethink how we manage roads. Some rationalization is in order.

See also Enterprising Roads.