Category Archives: transportation

Can We Live With Traffic?

The following text presents my first draft for a five minute presentation I’ve been asked to give.  I will be presenting this work on June 27th to a review committee selecting presenters for a TEDx event at Virginia Tech, to be held in November.  The content of this short presentation is much lighter than a full 15-minute TED talk, and I hope that I’ve made good use of the five minutes allotted me.  I would appreciate any feedback you wish to give regarding the presentation, especially constructive criticism that can help me to improve the talk.

Thank you very much for the opportunity to present my idea worth sharing to you.
To begin, I need to make a confession; I like traffic. 

It’s not that I enjoy traffic because it gives me more time to listen to NPR; I have my driveway for that.  I like traffic because, to me, each car on the road is a tiny proclamation of productivity.  Traffic gets created when we have places to live, jobs to go to, money to buy groceries with, and play-dates to take our kids to.
Unfortunately, the natural consequence of traffic is conflict. 
At the simplest of conventional intersections, there are 32 different points of conflict.  Every time you travel through an intersection, there are eight places where you cross the path of a conflicting vehicle.  The points at the beginning and end are called diverging and merging conflicts, and are far less dangerous than the crossing conflicts found in the middle of the intersection.

As frustrated as we might feel when waiting for a light to turn green, the sequencing of signalized intersections is designed to keep those conflicting movements out of your path.  Traffic engineers would like to think that the world is in balance, with control wiping out conflict, but the reality is very different.

Between the ages of 15 and 44, you’re more likely to die in an auto accident than from any other cause.  This is heart-wrenching for me, because traffic is killing people; specifically, it’s killing young people.  In their first year behind the wheel, one out of every sixteen people will be involved in a crash that ends with someone in the emergency room, either injured or dead.  This problem is a personal one for me.


Jonas will be eligible to drive in 2024, Emily in 2026, and Isaac in 2028.  My children are not statistics, they are people, and they are my world; I would do almost anything to keep them safe.  That being said, I want them to get their licenses as soon as they are able.  I refuse to let my fear prevent them from living a full life.  Instead, I choose to turn that fear into action, which is why I am here today.

So what’s the idea worth sharing?  How do we keep the traffic and beat the conflict?

There exists a group of designs known as “alternative intersections.”  They have names like the Jughandle, the Median U-turn, the Restricted Crossing U-turn, the Displaced Left-turn, the Quadrant Roadway, and the Modern Roundabout.  For today’s mini talk I’ll confine my discussion to some of the finer points of the Modern Roundabout.

By design, vehicles traveling through a roundabout are hard-pressed to travel above 20 miles an hour.  Impacts at lower speeds generally cause less damage and fewer injuries, but the largest benefit of this design for safety is in the area of conflict.
The roundabout reduces the 32 conflict points of a conventional intersection down to 8, completely removing crossing conflicts.  Accidents still happen at roundabouts, but cars merging and diverging at low speeds result in far fewer injuries or deaths.  So why not replace every signalized intersection with a roundabout?  It does well up to a certain amount of traffic, but it doesn’t make sense in every situation; it’s not a silver bullet.  Other alternative intersection designs, some of which exist only on paper today, can help solve the problem.

For a design that only exists on paper it’s easy to show a theoretical benefit to safety, but there’s a lot of fear that drivers won’t know what to do, and it’s impossible to say ‘the one they built over there is working great.’  Advocacy is necessary to bring these so-called “alternatives” into the mainstream.  We can’t wait any longer to embrace these designs.  People are dying, our youth are dying, and we need to fix it.  I want my children, all of our children, to become joyous sources of traffic: driving to school and their summer jobs, taking their dates to the prom, and going on road trips.  I’m anguished over the thought of them becoming an injury or fatality statistic, and I need your help to keep them safe.

Thank you.

Continue reading

Posted in Academia, alternative intersections, communicating science, roundabout, TED Talks, transportation, unconventional intersections, virginia tech

Can We Live With Traffic?

The following text presents my first draft for a five minute presentation I’ve been asked to give.  I will be presenting this work on June 27th to a review committee selecting presenters for a TEDx event at Virginia Tech, to be held in November.  The content of this short presentation is much lighter than a full 15-minute TED talk, and I hope that I’ve made good use of the five minutes allotted me.  I would appreciate any feedback you wish to give regarding the presentation, especially constructive criticism that can help me to improve the talk.

Thank you very much for the opportunity to present my idea worth sharing to you.
To begin, I need to make a confession; I like traffic. 

It’s not that I enjoy traffic because it gives me more time to listen to NPR; I have my driveway for that.  I like traffic because, to me, each car on the road is a tiny proclamation of productivity.  Traffic gets created when we have places to live, jobs to go to, money to buy groceries with, and play-dates to take our kids to.
Unfortunately, the natural consequence of traffic is conflict. 
At the simplest of conventional intersections, there are 32 different points of conflict.  Every time you travel through an intersection, there are eight places where you cross the path of a conflicting vehicle.  The points at the beginning and end are called diverging and merging conflicts, and are far less dangerous than the crossing conflicts found in the middle of the intersection.

As frustrated as we might feel when waiting for a light to turn green, the sequencing of signalized intersections is designed to keep those conflicting movements out of your path.  Traffic engineers would like to think that the world is in balance, with control wiping out conflict, but the reality is very different.

Between the ages of 15 and 44, you’re more likely to die in an auto accident than from any other cause.  This is heart-wrenching for me, because traffic is killing people; specifically, it’s killing young people.  In their first year behind the wheel, one out of every sixteen people will be involved in a crash that ends with someone in the emergency room, either injured or dead.  This problem is a personal one for me.


Jonas will be eligible to drive in 2024, Emily in 2026, and Isaac in 2028.  My children are not statistics, they are people, and they are my world; I would do almost anything to keep them safe.  That being said, I want them to get their licenses as soon as they are able.  I refuse to let my fear prevent them from living a full life.  Instead, I choose to turn that fear into action, which is why I am here today.

So what’s the idea worth sharing?  How do we keep the traffic and beat the conflict?

There exists a group of designs known as “alternative intersections.”  They have names like the Jughandle, the Median U-turn, the Restricted Crossing U-turn, the Displaced Left-turn, the Quadrant Roadway, and the Modern Roundabout.  For today’s mini talk I’ll confine my discussion to some of the finer points of the Modern Roundabout.

By design, vehicles traveling through a roundabout are hard-pressed to travel above 20 miles an hour.  Impacts at lower speeds generally cause less damage and fewer injuries, but the largest benefit of this design for safety is in the area of conflict.
The roundabout reduces the 32 conflict points of a conventional intersection down to 8, completely removing crossing conflicts.  Accidents still happen at roundabouts, but cars merging and diverging at low speeds result in far fewer injuries or deaths.  So why not replace every signalized intersection with a roundabout?  It does well up to a certain amount of traffic, but it doesn’t make sense in every situation; it’s not a silver bullet.  Other alternative intersection designs, some of which exist only on paper today, can help solve the problem.

For a design that only exists on paper it’s easy to show a theoretical benefit to safety, but there’s a lot of fear that drivers won’t know what to do, and it’s impossible to say ‘the one they built over there is working great.’  Advocacy is necessary to bring these so-called “alternatives” into the mainstream.  We can’t wait any longer to embrace these designs.  People are dying, our youth are dying, and we need to fix it.  I want my children, all of our children, to become joyous sources of traffic: driving to school and their summer jobs, taking their dates to the prom, and going on road trips.  I’m anguished over the thought of them becoming an injury or fatality statistic, and I need your help to keep them safe.

Thank you.

Continue reading

Posted in Academia, alternative intersections, communicating science, roundabout, TED Talks, transportation, unconventional intersections, virginia tech

Teaching’s a Joy in this Flat World

In the last month I’ve checked two books off of my list for summer reading, with seven remaining.

Source: Amazon.com
After reading the first 150 pages of The World is Flat by Thomas Friedman, barely a quarter of the full text, I decided to lend the book to a friend for the remainder of the summer.  My impression of the book thus far is that it’s fascinating, and that I’ll likely finish reading it someday, but for now I’ve got too much on my list to continue it.  Friedman’s book reads like a history of the last twenty years, as told through anecdote.  He examines how the dot com boom of the late nineties funded not just hordes of computer scientists to generate product, but also funded the construction of massive amounts of physical infrastructure that was left behind when the bubble burst.  In a classroom setting, this book could be well coupled with Andrew Blum’s book Tubes, which as it so happens was just reported on last week on NPR’s Fresh Air program.  The massive internet infrastructure built during the dot com boom provides data streams around the world that connects the highly developed countries that have high incomes to the less developed countries with lower incomes.  The moral of the story is that any work that can be sent elsewhere using a computer WILL be sent elsewhere using a computer in the very near future.

My purpose for adding this book to my summer reading list was because it appeared as required reading on a sample syllabus for a course I registered for this fall in engineering education.  I can only deduce that its purpose is to have future faculty members keep in mind that the engineers of the future, the students sitting in their classrooms today, will be expected to think critically and creatively in order to remain employed, and that we should build our learning objectives around these goals.  I’m glad I read it either way, as I’ve since found that this book may well come up in conversation among academics at any given time.  So okay, I got that message, now I’m moving on to the rest of my summer reading!

The kids: 2012-05-04
With Isaac’s birth this spring I’ve been faced with the daunting task of being a father to three kids under the age of four.  A natural consequence of this has been some stagnation of my research.  The balance we’ve found is that I spend 4:00 to 9:00 with the kids every evening, and then one full day each weekend not trying to get any work done.  I don’t think that five hours taken out of each day is what’s slowing me down relative to my peers, I think it’s the exhaustion of being “on” during those five hours every evening and remaining patient and supportive of my kids when I’m with them.  I was initially a bit panicked when I realized that I won’t be hitting my publication goals while in grad school, but I’ve come to terms with it a bit.  I realize that I don’t enjoy doing research full-time, and a career after grad school as a researcher wouldn’t be that much of an improvement over the consulting career I left, and what I really want to be doing is spending my time in the classroom.  Either way, I need to increase my productivity again.

Source: PhDComics
Source: PhDComics
The unfortunate reality is that ANY job in academia within engineering brings with it a research load, and every one of those jobs is being pursued with a vengeance by a hoard of recent graduates who have been publishing regularly (by regularly, I’m thinking four journal articles and eight conference papers during grad school).  Now that I’ve got myself into a tizzy again, I’ll come to the point; I’ve been feeling worn out and in need of some rejuvenation.  A vacation isn’t what I need; because that would put me even further behind on my research goals when I returned.  My proscribed bandaid for the problem is to put a couple of teaching books on my reading list.  The hope is that spending some time each week thinking about teaching will give my brain the processing time it needs to move the research forward, instead of just banging my head on my desk.  Which brings me to the second book I’ve finished from my summer reading list

Source: Amazon.com
The Joy of Teaching (a practical guide for new college instructors) by Peter Filene was an enjoyable, if brief read.  In a compact 133 pages, Filene lays out what you need to know going into your first full-time teaching position.

The first section of the book is intended to help academics place their mindset for their upcoming course before diving into it.  Chapter one asks the reader to examine their own beliefs and values as an educator, pointing out that each person has different strengths and weaknesses, and that a given style of instruction may work wonderfully for one person but awfully for another.  The second chapter builds off of these ideas and examines how different students operate.  Filene encourages the reader to understand the different kinds of cognition, and to recognize that any given classroom will contain a spectrum of students with different preferred learning styles, and different levels of preparation to take responsibility for their own learning.  The third chapter brings the first two chapters together and examines the aims and outcomes of a course.  Once the goals of a given course are understood, it’s time to move on to the application.

The second section of the book is titled practices; beginning with writing a syllabus and ending with evaluation, the section spends a great deal of time discussing lectures an discussions in the middle.  Though there weren’t any light bulbs turning on or bombshells dropped in the syllabus chapter, it was succinct, useful, and made the task of laying out a course feel entirely approachable.  The middle of the book, with chapters on lecturing, discussing, and broadening the learning environment, actually felt the weakest for me.  These chapters were as well-written and engaging as the rest of the book, but I struggled to connect many of the author’s ideas to engineering, because they were so firmly embedded in a history or sociology classroom.  This weakness continued into the evaluation chapter, as much of the time was spent discussing how best to provide constructive feedback without becoming overwhelmed by mountains of literary submittals.  At some point I’m sure the author had to make a decision about the breadth of their intended audience, and I certainly don’t hold it against them to stick to their specialty, I just found it a bit frustrating because their advice was so approachable I wanted more that was geared toward me.

The final section of the book brought up some important issues that weren’t otherwise covered, mainly focusing on creating balance in the workplace.  Filene provides an entire chapter on methods to create dialog between the instructor and the students, with a number of suggestions to increase communication outside of the classroom atmosphere, while simultaneously warning that office hours and emails can swallow up all of an instructor’s time if they are not careful.  I found one of Filene’s comments to be particularly insightful, where he says that “… week after week you sit alone, except during those two days before an exam when anxious students line up in the hall.  Don’t fault yourself or your students.  After all, how often have you visited your physician just to talk?”  Before wrapping up the book and reviewing the main points, Filene takes a chapter to discuss the concept of publish or perish, and how the truth of this statement varies greatly depending on what type of school you are employed by.

In all I found the Joy of Teaching to be informative, but not inspirational.  I’m thinking that perhaps the book would have been more accurately titled: “I know you think you’ll never survive your first year of this, but here are some coping mechanisms to help.  You’re going to be okay.”  Filene comes back to the idea of being lifted up by your time in the classroom, but even when he does there’s some angst built in, and you can’t quite escape the feeling that the glass is half empty.  One of the quotes from the book is supposed to show the positive aspect of teaching and comes from Nancy Greenwood, who says “I can have a crummy day with my kid.  I can have a crummy day with my colleagues.  But I can go into the classroom and most of the time leave and feel like I’ve done something good that day.”  Another example of semi-positive quotes from the book, this time on the topic of negative student reviews: as one of Filene’s colleagues likes to say, “even Jesus lost one out of twelve.”

I’m in the process of writing first drafts for this summer’s conference paper submittals, so I’m thinking that my next focus should be on the statistical analysis books from my reading list, but we’ll see where my free-time takes me.  Quantitative summaries of qualitative information derived from observations of data are apparently not a strong suit of mine, but something I need to work on.  In the back of my mind I can’t help but hear a little voice yelling “find a co-author!”  Until next time…

Continue reading

Posted in Academia, Grad School, instruction, reading, research, transportation

Teaching’s a Joy in this Flat World

In the last month I’ve checked two books off of my list for summer reading, with seven remaining.

Source: Amazon.com
After reading the first 150 pages of The World is Flat by Thomas Friedman, barely a quarter of the full text, I decided to lend the book to a friend for the remainder of the summer.  My impression of the book thus far is that it’s fascinating, and that I’ll likely finish reading it someday, but for now I’ve got too much on my list to continue it.  Friedman’s book reads like a history of the last twenty years, as told through anecdote.  He examines how the dot com boom of the late nineties funded not just hordes of computer scientists to generate product, but also funded the construction of massive amounts of physical infrastructure that was left behind when the bubble burst.  In a classroom setting, this book could be well coupled with Andrew Blum’s book Tubes, which as it so happens was just reported on last week on NPR’s Fresh Air program.  The massive internet infrastructure built during the dot com boom provides data streams around the world that connects the highly developed countries that have high incomes to the less developed countries with lower incomes.  The moral of the story is that any work that can be sent elsewhere using a computer WILL be sent elsewhere using a computer in the very near future.

My purpose for adding this book to my summer reading list was because it appeared as required reading on a sample syllabus for a course I registered for this fall in engineering education.  I can only deduce that its purpose is to have future faculty members keep in mind that the engineers of the future, the students sitting in their classrooms today, will be expected to think critically and creatively in order to remain employed, and that we should build our learning objectives around these goals.  I’m glad I read it either way, as I’ve since found that this book may well come up in conversation among academics at any given time.  So okay, I got that message, now I’m moving on to the rest of my summer reading!

The kids: 2012-05-04
With Isaac’s birth this spring I’ve been faced with the daunting task of being a father to three kids under the age of four.  A natural consequence of this has been some stagnation of my research.  The balance we’ve found is that I spend 4:00 to 9:00 with the kids every evening, and then one full day each weekend not trying to get any work done.  I don’t think that five hours taken out of each day is what’s slowing me down relative to my peers, I think it’s the exhaustion of being “on” during those five hours every evening and remaining patient and supportive of my kids when I’m with them.  I was initially a bit panicked when I realized that I won’t be hitting my publication goals while in grad school, but I’ve come to terms with it a bit.  I realize that I don’t enjoy doing research full-time, and a career after grad school as a researcher wouldn’t be that much of an improvement over the consulting career I left, and what I really want to be doing is spending my time in the classroom.  Either way, I need to increase my productivity again.

Source: PhDComics
Source: PhDComics
The unfortunate reality is that ANY job in academia within engineering brings with it a research load, and every one of those jobs is being pursued with a vengeance by a hoard of recent graduates who have been publishing regularly (by regularly, I’m thinking four journal articles and eight conference papers during grad school).  Now that I’ve got myself into a tizzy again, I’ll come to the point; I’ve been feeling worn out and in need of some rejuvenation.  A vacation isn’t what I need; because that would put me even further behind on my research goals when I returned.  My proscribed bandaid for the problem is to put a couple of teaching books on my reading list.  The hope is that spending some time each week thinking about teaching will give my brain the processing time it needs to move the research forward, instead of just banging my head on my desk.  Which brings me to the second book I’ve finished from my summer reading list

Source: Amazon.com
The Joy of Teaching (a practical guide for new college instructors) by Peter Filene was an enjoyable, if brief read.  In a compact 133 pages, Filene lays out what you need to know going into your first full-time teaching position.

The first section of the book is intended to help academics place their mindset for their upcoming course before diving into it.  Chapter one asks the reader to examine their own beliefs and values as an educator, pointing out that each person has different strengths and weaknesses, and that a given style of instruction may work wonderfully for one person but awfully for another.  The second chapter builds off of these ideas and examines how different students operate.  Filene encourages the reader to understand the different kinds of cognition, and to recognize that any given classroom will contain a spectrum of students with different preferred learning styles, and different levels of preparation to take responsibility for their own learning.  The third chapter brings the first two chapters together and examines the aims and outcomes of a course.  Once the goals of a given course are understood, it’s time to move on to the application.

The second section of the book is titled practices; beginning with writing a syllabus and ending with evaluation, the section spends a great deal of time discussing lectures an discussions in the middle.  Though there weren’t any light bulbs turning on or bombshells dropped in the syllabus chapter, it was succinct, useful, and made the task of laying out a course feel entirely approachable.  The middle of the book, with chapters on lecturing, discussing, and broadening the learning environment, actually felt the weakest for me.  These chapters were as well-written and engaging as the rest of the book, but I struggled to connect many of the author’s ideas to engineering, because they were so firmly embedded in a history or sociology classroom.  This weakness continued into the evaluation chapter, as much of the time was spent discussing how best to provide constructive feedback without becoming overwhelmed by mountains of literary submittals.  At some point I’m sure the author had to make a decision about the breadth of their intended audience, and I certainly don’t hold it against them to stick to their specialty, I just found it a bit frustrating because their advice was so approachable I wanted more that was geared toward me.

The final section of the book brought up some important issues that weren’t otherwise covered, mainly focusing on creating balance in the workplace.  Filene provides an entire chapter on methods to create dialog between the instructor and the students, with a number of suggestions to increase communication outside of the classroom atmosphere, while simultaneously warning that office hours and emails can swallow up all of an instructor’s time if they are not careful.  I found one of Filene’s comments to be particularly insightful, where he says that “… week after week you sit alone, except during those two days before an exam when anxious students line up in the hall.  Don’t fault yourself or your students.  After all, how often have you visited your physician just to talk?”  Before wrapping up the book and reviewing the main points, Filene takes a chapter to discuss the concept of publish or perish, and how the truth of this statement varies greatly depending on what type of school you are employed by.

In all I found the Joy of Teaching to be informative, but not inspirational.  I’m thinking that perhaps the book would have been more accurately titled: “I know you think you’ll never survive your first year of this, but here are some coping mechanisms to help.  You’re going to be okay.”  Filene comes back to the idea of being lifted up by your time in the classroom, but even when he does there’s some angst built in, and you can’t quite escape the feeling that the glass is half empty.  One of the quotes from the book is supposed to show the positive aspect of teaching and comes from Nancy Greenwood, who says “I can have a crummy day with my kid.  I can have a crummy day with my colleagues.  But I can go into the classroom and most of the time leave and feel like I’ve done something good that day.”  Another example of semi-positive quotes from the book, this time on the topic of negative student reviews: as one of Filene’s colleagues likes to say, “even Jesus lost one out of twelve.”

I’m in the process of writing first drafts for this summer’s conference paper submittals, so I’m thinking that my next focus should be on the statistical analysis books from my reading list, but we’ll see where my free-time takes me.  Quantitative summaries of qualitative information derived from observations of data are apparently not a strong suit of mine, but something I need to work on.  In the back of my mind I can’t help but hear a little voice yelling “find a co-author!”  Until next time…

Continue reading

Posted in Academia, Grad School, instruction, reading, research, transportation

First Draft for Virginia Tech TEDx

This post is a little different from my usual content.


My dissertation research focus is on alternative intersection designs, and I am committed to spreading the word about these designs as far as I can.  To this end, I am nominating myself to speak at the upcoming Virginia Tech TEDx event on November 10, 2012.  Speakers will be chosen from among the students, faculty, and staff at the University.  I’ve written a first draft for the presentation I wish to give, should I be chosen to participate in the event.  It’s designed to be around 15 minutes in length, so it’s not a quick read.  If you have the time, I strongly suggest you read the post because I feel that the information is important.  If you are a student, alumnus, faculty, or staff member at Virginia Tech, and you agree that this information should be presented at the upcoming TEDx event, I would be very grateful if you could add your nomination to my own before the May 18th nomination deadline arrives.


Thank you,  John

Good afternoon, my name is John Sangster, and I’d like to start off my talk today with a confession: I like traffic. When I tell people that I’m a traffic engineer, the way I’m sometimes looked at makes me understand how divorce lawyers must feel; everyone knows that our jobs are necessary, but everyone wishes that they weren’t. Okay, so what’s that I said about liking traffic?

It’s not that I enjoy traffic because it gives me more time to listen to NPR, I’ve got my driveway for that. I like traffic because each car on the road means people are busy living their lives. Traffic is created whenever we have places to live, jobs to go to, money to buy groceries with, and play-dates to take our kids to. Sometimes I feel like each car on the road is like a small proclamation of productivity.

The reason I have a job, and the reason why I am here today to talk with you, is that individual trips are wonderful things, but having more than one car on the road naturally leads to conflict. Lots of cars on the road at the same time leads to lots of conflict. This idea of conflict is used within my industry to better understand and control the flow of traffic on the roads. The next time you drive through an intersection, I’d like you to ponder this concept of conflict.

Source: Federal Highway Administration

The simplest of intersections, with only one lane approaching from each direction, contains 32 different points of conflict. Each time you go straight through an intersection, there are six different points where you are passing through the path of another vehicle. The first two points are called diverging points, where cars traveling on the same path separate into different paths. These diverging points are a source of rear-end collisions, when a following vehicle makes an assumption that the leader will continue through, and for some reason the leading vehicle is forced to stop. The next four points of conflict you pass through are called crossing points; these locations are the most dangerous, and are the cause of head-on and T-bone collisions. The last two points you pass through are a bit less stressful; they’re called merging conflict points, and involve vehicles from separate paths coming together to move in the same direction; these conflicts usually result in side-swipe collisions, and are usually limited to property damage with many fewer injuries or deaths. The reason I want you to think about these conflicts when you’re out on the road driving, is because I’d like you to be a little more patient when waiting at a red light. There are good reasons for signalizing an intersection, and one of the best is to make sure that the other cars driving through it aren’t going to be in conflict with you!

Source: Federal Highway Administration

Tolkien was wrong; it takes two rings to rule them all. Common practice in the United States is to organize traffic movements according to the “ring and barrier design” as shown in the graphic. The power of the conceptualization is that it separates all of those conflicts we discussed so that nothing overlaps. Each individual movement cannot occur simultaneously with any movement in its row, or any movement located on the other side of a barrier from it. For example, movement one, a northbound left-turn, can only occur simultaneously with movements five or six, a southbound left-turn or a northbound through/right movement.

Now the world is in balance: we’ve got conflict, and we’ve got a control scheme to fix it; right? So how successful have traffic engineers been at keeping you safe on the roads? Not very.

The leading cause of death in the United States for people between the ages of 15 and 44 is motor vehicle fatalities. Let me say it again more slowly, because this is heart-wrenching for me; the leading cause of death for young people is from driving. According to the Federal Highway Administration, there were 2.5 million intersection-related crashes in 2007, 37,000 of which resulted in a fatality. For crashes resulting in injury or death, the highest rate is among 16-year old drivers, who experience 61.4 crashes per 1,000 drivers. I have trouble conceptualizing how much 61 out of 1,000 is, but I find it very easy to understand when put another way.

Among high school juniors, one student out of every sixteen will be behind the wheel of a car that is involved in a crash in which someone is injured or killed. I like the way that this image makes the statistic more relatable, but it still feels impersonal to me. I have three incredibly important, and very personal, reasons for the work that I do.

My son Jonas loves reading non-fiction books – his current favorite topic is space and the planets. His favorite color is orange. When he arrives at pre-school in the morning, he likes to sit on a bench for the first five minutes by himself quietly watching the other kids play before he ventures out to join them. He will be eligible to get his driver’s license in July of 2024.

My daughter Emily is extremely friendly and very polite, so long as you’re doing exactly what she wants. She likes to wear “piggy tails,” though she rarely sits still while I fix her hair in the morning. Her favorite color is purple. She likes to browse books at bedtime, and nearly every time I go in to turn out her light she’s got a book lying on her face. She will be eligible to get her driver’s license in April of 2026.

My son Isaac likes to sit on my lap and chat with me. I’m not sure what he’s saying most of the time; he keeps talking about some lady named “Nnnnnga” that I have yet to meet. He’ll be eligible to get his driver’s license in February of 2028.

I tell you these details because my children are not statistics, they are people; they are my life, and I would do anything to keep them safe.

I’ve now taken eight minutes of your time. I’ve explained why traffic can be a positive thing and should be valued, how it creates conflict, and how traffic engineers have been trying to control that conflict. I’ve explained the extent to which we’re failing to keep you safe, and why it’s personally important to me to change it. With the seven minutes that remain of my allotted time, I’d like to talk to you about recent developments in intersection design, which I believe to be part of the solution.

In the last five years a group of intersection designs have been given their own classification as “alternative intersections.” These designs have names like the Jughandle, the Median U-turn, the Restricted Crossing U-turn, the Displaced Left-turn, the Quadrant Roadway, and one that should be very familiar to the audience here today, the Modern Roundabout. Some of these designs have been regionally accepted for many years, such as the Jughandle in New Jersey or the Median U-turn in Michigan, but I’d like to focus the talk today on the two designs which have been gaining wider acceptance only recently. I’ll finish up by talking about the use of the Restricted Crossing U-turn design, but at the moment I want to discuss some of the finer points of the Modern Roundabout.

Source: Google Maps

I’m careful to specify this design as the modern roundabout, because it’s very different from the rotaries popular in the northeastern US fifty years ago. The diameter of the circle in this design is set as small as possible; only large enough to force cars to slow down as they travel through the intersection. Vehicles traveling through a roundabout are hard-pressed to travel above 20 miles an hour, which greatly increases safety, but this is not the most dramatic safety effect that we see.

If you remember only one thing from today’s presentation, I want it to be the image on the screen right now. Traffic begets conflict, there’s no escaping it, so traffic engineers attempt to control it. We fail at this, and people die. The reason why so many places are embracing the roundabout is that we go from 32 points of conflict to 8, and we completely remove all of the incredibly dangerous crossing conflicts. Accidents still happen at roundabouts, but the angle-type accidents that occur result in far fewer injuries and deaths.

As Americans we’re often known for embracing innovation. I’ll point to the state of Virginia as a positive example of this: in 2004 the first modern roundabout intersection was constructed in the state, and by 2008 the State’s road design manual was updated to say that whenever a roundabout will work for a given location, the state prefers it over the conventional design. I was pretty impressed when I found this out, because it feels like a huge accomplishment to make that large of a policy shift in a four year period. As fast as we’re adopting the design though, we’re still way behind the curve. The latest number I’ve seen says that the United States has installed 3,000 of these intersections; in contrast, there are 25,000 of them in the United Kingdom, and 30,000 of them in France. So why aren’t we replacing every signalized intersection with a roundabout? It’s because the roundabout is not a silver bullet; it performs wonderfully up to a certain level of traffic flow, working particularly well at places with lots of turning vehicles, but it doesn’t make sense in every situation.

Source: see ATTAP for video

In some cases where a major street and a minor street meet, there’s too much through traffic on the major street to accommodate a roundabout and we need a different solution. North Carolina has been using the Restricted Crossing U-turn on high-volume roads for a couple of years now, and they’re happy with the results. This design allows major street traffic to move in any direction it wishes, but makes the minor street approaches turn right, forcing them to make a U-turn down the road if they intend to cross through to the other side or take a left-turn. The ring-and-barrier design I discussed earlier comes into play here: by getting rid of the left-turn phase on the minor street approach more of the green-time can be given to the major street traffic. A small number of vehicles approaching on the minor streets take a much longer time to travel through the intersection, but a large number of vehicles approaching on the major street take a bit shorter time traveling through, generally breaking even overall. We’ve checked off the “do no harm” requirement for traffic mobility, so how does it perform for safety?

Source: Federal Highway Administration

This design isn’t as clean as a roundabout for safety, but it’s better than a conventional intersection, and it works in situations a roundabout does not. In all, we reduce the conflict points from 32 to 20, with the all-important crossing conflicts reduced from 16 down to 2. This is just an example of the types of designs that are available to replace our antiquated conventional signalized intersections.

You’ve given me fifteen minutes of your time and I greatly appreciate it, but I have a favor to ask of you. I need you to tell your friends about this; I need you to tell your colleagues about this; I need you to tell your elected officials about this. We can’t wait any longer to embrace these alternative designs. People are dying, our youth are dying, and we need to fix it. I can stand up here and talk until my voice goes hoarse about why we should build these and what is at stake, but I can’t change the world without your help. I want my children, all of our children, to become joyous sources of traffic: driving to school or their summer job, taking their dates to prom, or going on a road trip. I’m anguished over the thought of them becoming an injury or fatality statistic, and I need your help to keep them safe. Thank you. Continue reading

Posted in Academia, alternative intersections, communicating science, roundabout, TED Talks, transportation, unconventional intersections, virginia tech

First Draft for Virginia Tech TEDx

This post is a little different from my usual content.


My dissertation research focus is on alternative intersection designs, and I am committed to spreading the word about these designs as far as I can.  To this end, I am nominating myself to speak at the upcoming Virginia Tech TEDx event on November 10, 2012.  Speakers will be chosen from among the students, faculty, and staff at the University.  I’ve written a first draft for the presentation I wish to give, should I be chosen to participate in the event.  It’s designed to be around 15 minutes in length, so it’s not a quick read.  If you have the time, I strongly suggest you read the post because I feel that the information is important.  If you are a student, alumnus, faculty, or staff member at Virginia Tech, and you agree that this information should be presented at the upcoming TEDx event, I would be very grateful if you could add your nomination to my own before the May 18th nomination deadline arrives.


Thank you,  John

Good afternoon, my name is John Sangster, and I’d like to start off my talk today with a confession: I like traffic. When I tell people that I’m a traffic engineer, the way I’m sometimes looked at makes me understand how divorce lawyers must feel; everyone knows that our jobs are necessary, but everyone wishes that they weren’t. Okay, so what’s that I said about liking traffic?

It’s not that I enjoy traffic because it gives me more time to listen to NPR, I’ve got my driveway for that. I like traffic because each car on the road means people are busy living their lives. Traffic is created whenever we have places to live, jobs to go to, money to buy groceries with, and play-dates to take our kids to. Sometimes I feel like each car on the road is like a small proclamation of productivity.

The reason I have a job, and the reason why I am here today to talk with you, is that individual trips are wonderful things, but having more than one car on the road naturally leads to conflict. Lots of cars on the road at the same time leads to lots of conflict. This idea of conflict is used within my industry to better understand and control the flow of traffic on the roads. The next time you drive through an intersection, I’d like you to ponder this concept of conflict.

Source: Federal Highway Administration

The simplest of intersections, with only one lane approaching from each direction, contains 32 different points of conflict. Each time you go straight through an intersection, there are six different points where you are passing through the path of another vehicle. The first two points are called diverging points, where cars traveling on the same path separate into different paths. These diverging points are a source of rear-end collisions, when a following vehicle makes an assumption that the leader will continue through, and for some reason the leading vehicle is forced to stop. The next four points of conflict you pass through are called crossing points; these locations are the most dangerous, and are the cause of head-on and T-bone collisions. The last two points you pass through are a bit less stressful; they’re called merging conflict points, and involve vehicles from separate paths coming together to move in the same direction; these conflicts usually result in side-swipe collisions, and are usually limited to property damage with many fewer injuries or deaths. The reason I want you to think about these conflicts when you’re out on the road driving, is because I’d like you to be a little more patient when waiting at a red light. There are good reasons for signalizing an intersection, and one of the best is to make sure that the other cars driving through it aren’t going to be in conflict with you!

Source: Federal Highway Administration

Tolkien was wrong; it takes two rings to rule them all. Common practice in the United States is to organize traffic movements according to the “ring and barrier design” as shown in the graphic. The power of the conceptualization is that it separates all of those conflicts we discussed so that nothing overlaps. Each individual movement cannot occur simultaneously with any movement in its row, or any movement located on the other side of a barrier from it. For example, movement one, a northbound left-turn, can only occur simultaneously with movements five or six, a southbound left-turn or a northbound through/right movement.

Now the world is in balance: we’ve got conflict, and we’ve got a control scheme to fix it; right? So how successful have traffic engineers been at keeping you safe on the roads? Not very.

The leading cause of death in the United States for people between the ages of 15 and 44 is motor vehicle fatalities. Let me say it again more slowly, because this is heart-wrenching for me; the leading cause of death for young people is from driving. According to the Federal Highway Administration, there were 2.5 million intersection-related crashes in 2007, 37,000 of which resulted in a fatality. For crashes resulting in injury or death, the highest rate is among 16-year old drivers, who experience 61.4 crashes per 1,000 drivers. I have trouble conceptualizing how much 61 out of 1,000 is, but I find it very easy to understand when put another way.

Among high school juniors, one student out of every sixteen will be behind the wheel of a car that is involved in a crash in which someone is injured or killed. I like the way that this image makes the statistic more relatable, but it still feels impersonal to me. I have three incredibly important, and very personal, reasons for the work that I do.

My son Jonas loves reading non-fiction books – his current favorite topic is space and the planets. His favorite color is orange. When he arrives at pre-school in the morning, he likes to sit on a bench for the first five minutes by himself quietly watching the other kids play before he ventures out to join them. He will be eligible to get his driver’s license in July of 2024.

My daughter Emily is extremely friendly and very polite, so long as you’re doing exactly what she wants. She likes to wear “piggy tails,” though she rarely sits still while I fix her hair in the morning. Her favorite color is purple. She likes to browse books at bedtime, and nearly every time I go in to turn out her light she’s got a book lying on her face. She will be eligible to get her driver’s license in April of 2026.

My son Isaac likes to sit on my lap and chat with me. I’m not sure what he’s saying most of the time; he keeps talking about some lady named “Nnnnnga” that I have yet to meet. He’ll be eligible to get his driver’s license in February of 2028.

I tell you these details because my children are not statistics, they are people; they are my life, and I would do anything to keep them safe.

I’ve now taken eight minutes of your time. I’ve explained why traffic can be a positive thing and should be valued, how it creates conflict, and how traffic engineers have been trying to control that conflict. I’ve explained the extent to which we’re failing to keep you safe, and why it’s personally important to me to change it. With the seven minutes that remain of my allotted time, I’d like to talk to you about recent developments in intersection design, which I believe to be part of the solution.

In the last five years a group of intersection designs have been given their own classification as “alternative intersections.” These designs have names like the Jughandle, the Median U-turn, the Restricted Crossing U-turn, the Displaced Left-turn, the Quadrant Roadway, and one that should be very familiar to the audience here today, the Modern Roundabout. Some of these designs have been regionally accepted for many years, such as the Jughandle in New Jersey or the Median U-turn in Michigan, but I’d like to focus the talk today on the two designs which have been gaining wider acceptance only recently. I’ll finish up by talking about the use of the Restricted Crossing U-turn design, but at the moment I want to discuss some of the finer points of the Modern Roundabout.

Source: Google Maps

I’m careful to specify this design as the modern roundabout, because it’s very different from the rotaries popular in the northeastern US fifty years ago. The diameter of the circle in this design is set as small as possible; only large enough to force cars to slow down as they travel through the intersection. Vehicles traveling through a roundabout are hard-pressed to travel above 20 miles an hour, which greatly increases safety, but this is not the most dramatic safety effect that we see.

If you remember only one thing from today’s presentation, I want it to be the image on the screen right now. Traffic begets conflict, there’s no escaping it, so traffic engineers attempt to control it. We fail at this, and people die. The reason why so many places are embracing the roundabout is that we go from 32 points of conflict to 8, and we completely remove all of the incredibly dangerous crossing conflicts. Accidents still happen at roundabouts, but the angle-type accidents that occur result in far fewer injuries and deaths.

As Americans we’re often known for embracing innovation. I’ll point to the state of Virginia as a positive example of this: in 2004 the first modern roundabout intersection was constructed in the state, and by 2008 the State’s road design manual was updated to say that whenever a roundabout will work for a given location, the state prefers it over the conventional design. I was pretty impressed when I found this out, because it feels like a huge accomplishment to make that large of a policy shift in a four year period. As fast as we’re adopting the design though, we’re still way behind the curve. The latest number I’ve seen says that the United States has installed 3,000 of these intersections; in contrast, there are 25,000 of them in the United Kingdom, and 30,000 of them in France. So why aren’t we replacing every signalized intersection with a roundabout? It’s because the roundabout is not a silver bullet; it performs wonderfully up to a certain level of traffic flow, working particularly well at places with lots of turning vehicles, but it doesn’t make sense in every situation.

Source: see ATTAP for video

In some cases where a major street and a minor street meet, there’s too much through traffic on the major street to accommodate a roundabout and we need a different solution. North Carolina has been using the Restricted Crossing U-turn on high-volume roads for a couple of years now, and they’re happy with the results. This design allows major street traffic to move in any direction it wishes, but makes the minor street approaches turn right, forcing them to make a U-turn down the road if they intend to cross through to the other side or take a left-turn. The ring-and-barrier design I discussed earlier comes into play here: by getting rid of the left-turn phase on the minor street approach more of the green-time can be given to the major street traffic. A small number of vehicles approaching on the minor streets take a much longer time to travel through the intersection, but a large number of vehicles approaching on the major street take a bit shorter time traveling through, generally breaking even overall. We’ve checked off the “do no harm” requirement for traffic mobility, so how does it perform for safety?

Source: Federal Highway Administration

This design isn’t as clean as a roundabout for safety, but it’s better than a conventional intersection, and it works in situations a roundabout does not. In all, we reduce the conflict points from 32 to 20, with the all-important crossing conflicts reduced from 16 down to 2. This is just an example of the types of designs that are available to replace our antiquated conventional signalized intersections.

You’ve given me fifteen minutes of your time and I greatly appreciate it, but I have a favor to ask of you. I need you to tell your friends about this; I need you to tell your colleagues about this; I need you to tell your elected officials about this. We can’t wait any longer to embrace these alternative designs. People are dying, our youth are dying, and we need to fix it. I can stand up here and talk until my voice goes hoarse about why we should build these and what is at stake, but I can’t change the world without your help. I want my children, all of our children, to become joyous sources of traffic: driving to school or their summer job, taking their dates to prom, or going on a road trip. I’m anguished over the thought of them becoming an injury or fatality statistic, and I need your help to keep them safe. Thank you. Continue reading

Posted in Academia, alternative intersections, communicating science, roundabout, TED Talks, transportation, unconventional intersections, virginia tech

Summer Days, Drifting Away

The semester has ended, and summer is upon us.  Last summer I poured myself into research, and worked seven days a week on data reduction in order to get three papers submitted for the August 1 deadline for the big conference in my field.  Only one paper was accepted, and it ended up being my hobby paper, entirely unrelated to my thesis.  I’m in a different mental place this year, and I plan to submit whatever gets done between now and then; it’s not worth burning myself out to accomplish more.

As part of my effort to re-center and reactivate myself I’ve decided to set aside Fridays to study away from the house and away from the lab.  I plan to work on developing the Achieve Academe thing (I really need to come up with better ways to describe it) that’s been started, flesh out my webpage, and do some reading.  I keep hearing other people talk about summer reading, and I want to jump on that band wagon, though I think people might not agree with my recreational reading choices.

First up on my list of summer books are the textbooks that are required reading for the coming school year.  Next year will be my last year of classes, and I’m splitting it evenly between statistics and engineering education.  Some of these books I’m more excited to read than others, but I think I’ll enjoy them all.

In addition to the required texts, I’ve added a few more to my reading list…

Transportation Statistics and Microsimulation, by Spiegelman, Park, and Rilett

If for some bizarre reason I finish all of the books on my plate, what else along this vein should I be reading? What are your favorite books on education?  What books have you read that changed the way you looked at the world?

Continue reading

Posted in Academia, Grad School, instruction, reading, transportation

Summer Days, Drifting Away

The semester has ended, and summer is upon us.  Last summer I poured myself into research, and worked seven days a week on data reduction in order to get three papers submitted for the August 1 deadline for the big conference in my field.  Only one paper was accepted, and it ended up being my hobby paper, entirely unrelated to my thesis.  I’m in a different mental place this year, and I plan to submit whatever gets done between now and then; it’s not worth burning myself out to accomplish more.

As part of my effort to re-center and reactivate myself I’ve decided to set aside Fridays to study away from the house and away from the lab.  I plan to work on developing the Achieve Academe thing (I really need to come up with better ways to describe it) that’s been started, flesh out my webpage, and do some reading.  I keep hearing other people talk about summer reading, and I want to jump on that band wagon, though I think people might not agree with my recreational reading choices.

First up on my list of summer books are the textbooks that are required reading for the coming school year.  Next year will be my last year of classes, and I’m splitting it evenly between statistics and engineering education.  Some of these books I’m more excited to read than others, but I think I’ll enjoy them all.

In addition to the required texts, I’ve added a few more to my reading list…

Transportation Statistics and Microsimulation, by Spiegelman, Park, and Rilett

If for some bizarre reason I finish all of the books on my plate, what else along this vein should I be reading? What are your favorite books on education?  What books have you read that changed the way you looked at the world?

Continue reading

Posted in Academia, Grad School, instruction, reading, transportation

Exposure, Disclosure, and Promotion

Recently in my course on Contemporary Pedagogy we had a guest speaker.  Jon Udell came in to talk to us about “web thinking” and his career working in a collaborative web environment.  In reading a bit of the prolific material that Mr. Udell … Continue reading

Posted in Academia, Blogging, communicating science, Grad School, instruction, research, transportation, virginia tech, web presence

Exposure, Disclosure, and Promotion

Recently in my course on Contemporary Pedagogy we had a guest speaker.  Jon Udell came in to talk to us about “web thinking” and his career working in a collaborative web environment.  In reading a bit of the prolific material that Mr. Udell … Continue reading

Posted in Academia, Blogging, communicating science, Grad School, instruction, research, transportation, virginia tech, web presence