CE 572 - Intersection Traffic Operations
Spring 2007

Website of the day:
Road Engineering Journal - Walking Speed Study

Objectives for today:

• to better understand permitted left turn operations and capacity
• to learn about pedestrian characteristics

Topics:

• Permitted left turn operations
• Pedestrian study
• Assessment
• Next steps

Class notes:
Written notes
Slides (none available for this class meeting)

Assignment 6
The purpose of this assignment is to understand the characteristics of another user group: pedestrians.  In this assignment, you will collect data on the pedestrian timing intervals, the walking speed of pedestrians, and the start up time of pedestrians at the beginning of the walk or green interval.  This assignment is due on Thursday, February 22, at noon via email.

Step 1. Note the following conditions about your assigned location:

• The pedestrian crossing path (location) that you are observing.
• The weather at the time of your data collection.
• The date and time of day of your data collection.
• Brief description of the pedestrian crossing environment.

Step 2. Record the Walk, Flashing Don't Walk, and Don't Walk intervals for five sets of pedestrian intervals.  Record the start of the Flashing Don't Walk and the Don't Walk intervals as compared with the start of the Yellow vehicle interval.

Step 3. Record for 25 pedestrians, the time from when the pedestrian stepped off the curb until the pedestrian stepped on the curb at the far side of the crosswalk.  Your measurements should be to the nearest 0.1 second.  For each pedestrian, note the approximate age and degree of mobility.

Step 4. Record for 25 pedestrians, the time from the beginning of the Walk or Green interval to the time that the pedestrian steps off the curb.  Your measurement should be to the nearest 0.1 second.

Use this data collection form for your data.

Reading Assignment
On February 22, we will begin our study of detection systems, one of the four components of the traffic control system.  In preparation for this class, please read the following material.  The following study questions should help to guide your reading.

Design Guidelines for Deploying Closed Loop Systems, pp 21-25.
Manual of Traffic Signal Design (chapter 7)
Manual of Traffic Detector Design (excerpts), pp 19-23

Study questions:
1. What are some of the standard detector types?
2. What are the features of short loop and long loop detectors?
3. What are the locking and non-locking features?
4. What are the considerations in location of detectors?
5. What are the two primary loop detector modes of operation?
6. What is call-delay and call-extend operation?

Assessment
"Assessment is the process of measuring and analyzing performance to provide timely feedback to improve future performance. Assessment differs from evaluation in that it provides opportunities for feedback, improvement, and revision; identifies strengths, areas for improvement, and ways to improve; and is non-judgmental, frequent, and congruent with the learning goals."

• What have you liked about the class so far?
• What aspects of the class have positively supported your learning about traffic signal systems?
• What aspects of the class have negatively impacted your learning about traffic signal systems?
• What suggestions would you make to me to improve the class for the remainder of the semester?
• If you could tell me two things about the class they would be (1) … and (2) …

Assessment Results
1. What have you liked about the class so far?

• The experience of the professor.
• Working with real world stochastic data.
• Data extraction and reduction steps to estimate useful parameters.
• The use of real world data in the assignments
• The questions after each class are good.
• Everything, in short.  I especially liked working with the Lankershim video data; exposure to real world data gave me a glimpse of on road conditions and made me think about the factors causing variability in observations.
• I have liked that we have had many different homework assignments.  I liked that we have had to give small presentations from time to time.  I think this is important, but I like that they have been semi-casual.  The presentations do not need to make us students nervous.  I like that they are short and do not carry a lot of pressure as far as grades are concerned.
• I liked the group assignment (A04).  I thought having someone else's input while doing the analysis for A03 was beneficial.  I have also enjoyed the brief introduction to Visual Basic.  It was nice to get to use it, but not be expected to know how to write code right away.
• I liked the study of headways and its effects on signal timing.
• Response to questions at the end of class helped to clarify our doubts.  And to know how other classmates learned from the lectures.
• It is very informative and well organized.  Each new topic builds on previous ones, which greatly improves my understanding of the material.
• Questions and answers (after each class) that are posted on the web site.
• I have liked the idea of working assignments with real world data.
• I like the knowledge that I have acquired in this class regarding what actually happens at a signalized intersection (arrival and departure patterns of vehicles)
• I like the comments that the professor adds in grading the assignments.
• The work assignments take time but they go a long way in assisting my work.

2. What aspects of the class have positively supported your learning about traffic signal systems?

• The assignments
• Focus on the insight of each sub system which helps us to understand different traffic engineering phenomenon clearly.
• The interpretation of graphs and diagrams.  Understand when and why set up the parameters for signalized intersections, e.g. passage time.
• The course is laid out very systematically and I really appreciate it so far.  Also, I prefer it when a professor maintains a level of interactivity with the students during the class.
• The posting of the questions and lecture notes have helped me in a positive way.  I find the class web site VERY helpful.
• The aspects of class that have positively supported my learning about traffic signal systems are the lectures and homework assignments.  Beginning with the first lecture and assignment, I feel that my knowledge and understanding of traffic signal systems has grown.
• Assignments helped me to think about what we learned in class.
• Relationship between detection zone length and unoccupancy is useful to determine passage time.
• Manual homeworks are long but help us to understand the core of the analysis.
• The assignments done with the Lankershim data have probably been the most beneficial to me.  I now have a much clearer picture of how vehicles interact with other vehicles at intersections.
• Working with field data (Lankershim data) helps me to learn how to look and filter field data and analyze it.
• Talking what I have learned in class and trying to apply it in the real world.
• The class presentations and online questions and answers makes me understand more about an area about which I wasn't clear.

3. What aspects of the class have negatively impacted your learning about traffic signal systems?

• None.
• None.
• There is useful reading the the time is not enough.
• None come to mind.  The homework load is a bit harder than anticipated, although it has obviously not "negatively impacted my learning" or anything.  If anything, I liked doing these.  I also really appreciate the easy grading of the homeworks.
• I don't like dealing with large data sets. I understand that we need to manipulate our own data so that we can learn more from the process, but the data was too large.  My computer, and the school computers, could not process the data quickly.  It took several minutes to save the data.  Sometimes processing the data caused the operating system to crash.
• A negative impact to my learning was assignment 3.  This particular assignment had great content, but was so detail oriented and time consuming (especially if you messed it up and had to redo the entire thing).  It would have been better to do this assignment with a partner to share the large work load.
• None.
• None.
• I really can't think of anything so far that has negatively impacted what I've learned so far in the class.
• None.
• Since no textbook is available, I find it is sometimes difficult it is sometimes difficult to understand some topics or statements.

4. What suggestions would you make to me to improve the class for the remainder of the semester?

• To organize more working in teams.  I can see that this is coming.
• Before finishing up a topic, ideas should be given to the student about what more they can learn about the topic but that we couldn't cover.
• Encourage us to participate more in class.
• At this time I do not have any suggestions/comments which would improve the class.  If anything comes to mind, I'll let you know.
• Do not require us to work with "large" data sets.  I like the idea of emailing questions everyday but I don't have "intelligent" questions everyday.  I don't want to feel like I am going to waste your time with a silly question, but sometimes I don't have any questions.  I don't know what a good question would be.  Maybe we should be required to ask three questions every week and that should just be emailed to you by 200 pm every Thursday.
• For the remainder of the semester, I would suggest allowing assignments to be completed in teams that the class members select.  The team assignment format worked will in public transportation class, and it should work well here.  This would improve the class format.
• Its better if you could post the slides of class early, perhaps four hours before class.
• Sometimes I can't print the slides.  Its a problem with the printer or the size of the files.
• I would like to see more group work.  The first few Lankershim assignments were a lot of work for just one person and would have been much easier to complete with an additional person or two.
• I like the way you teach and design the class lectures and assignments.

5. If you could tell me two things about the class they would be (1) … and (2) …

• To have access to new material presented during the class.  For instance, the theory of gap acceptance.
• Assignments are really interesting.
• Lecture are well organized.
• I like that this class is really full of knowledge; you are always prepared.
• I hope that the exam will be understandable.
• The class is engaging and interactive.
• The class is the right size.  I like that this class consists of about a dozen students.  This is a good professor-student ratio.
• The class keeps me busy, but I know that in the end I will feel like I have learned a lot.
• The information presented is very interesting.
• It is difficult having a class that is 1.25 hours long over lunch time.  First I get hungry and then I get sleepy.  It becomes really hard to pay attention.  But besides that, this class is fine.  And I would really like the assignments to be a team format.
• Very interesting.
• The topic is relevant to our lives.
• Always interesting and productive.
• It is well planned.  Each new topic builds on things discussed previously, which helps me to understand the topics more completely.
• For what some people would consider a fairly dry and boring subject, I have found the class so far to be very informative and interesting.
• I like that assignments focus more on analysis than writing.
• More real world examples and videos.