Comments/Questions from Class 01
General comments
Questions about the class
Preparing/studying for this class
Detectors
General comments
- I was surprised to hear we would be focusing on only intersections the entire semester.
- The overall concept of the class seems to interest me and I am looking forward to the group work. I prefer to work in groups, I firmly believe that group working is one of the best ways to learn.
- Interested on learning more about the VISSIM program. I have seen it in action it will be interesting to lean it myself.
- I am excited for the lab portion of the class. I always like applying what I am learning to better understand the material.
- "Traffic controller" is a whole new term i have not heard before.
- I worked for ITD as a traffic intern, be interesting to see a lot more information from your class, as I just did simple field work.
- Be interested in learning more about the different phases and ring diagrams also.
- One thing I enjoyed about today's class was the way you differentiated CE 474 from CE 372 with “connecting the loop”.
- Something I am looking forward to in this class is the coordination of a traffic system as a whole and focusing on multiple intersections.
- During class we discussed the user, detection, controller, display systems used at traffic intersections. These systems insure that an intersection can maximize flow output.
- We discussed a traffic control process diagram, which is used to process the data for the controller to process the vehicles through the intersection.
- I noticed in class that you mentioned a few times about having to make a lot of presentations and oral exams. I am not a great public speaker so this makes me nervous, but at the same time I am glad that is happening because I need more experience in this.
- I am looking forward to the projects in this course.
- Over the summer I worked as a transportation intern and never learned about signal detection, but I was always curious about it. I'm very excited to learn more about the process.
Questions about the class
- Will there be some/any over lap between the two projects? Yes there will be some overlap. One primary link is that the single intersection that you do in your first project is part of the system that you will study in your second project.
- Will we be using any programming software for the course such as Mathcad, Excel VBA or Viper? Not directly. However, all of your data analysis and management will be done in Excel and there is some VBA code built into some of the spreadsheets that you use. My guess is that you will be far greater experts in using some of Excel's important functions than before you started this class.
- Will we be using VISSIM traffic model ? Yes.
- How valuable is a Master's degree in a transportation engineering career? Are the 500- level courses worth more than the 2 years of work experience? While this varies based on your individual goals, my sense is that a Master's degree is well worth the additional two years required. You have the chance to dig deeper into the field and most students find that this time greatly helps their confidence when they start work in the profession.
- How do the values of traffic systems design courses vs. geometric design and pavement design courses compare depending on where a beginning engineer seeks employment? (i.e. rural vs. urban, private consulting firm vs. DOT/county, etc.) If a student only has room in their schedule for 2 transportation/pavement courses and plans to seek employment in a rural area, which courses are the most valuable? Again, this will likely differ case by case. Many local or state organizations do more design work (particularly pavements and geometrics) while consulting firms often have focus on operations (which would include traffic control systems work). I'd be happy to discuss this more if there is interest in this topic.
- Should we bring our textbooks to class and lab every day? YES!
Preparing/studying for this class
- How would you recommend studying for your exams?
- I would like to know more about the oral examinations. Are they individual or group, and what I can expect to do for them. What is the length of the examination?
- Do you have any helpful tips for study habits or note taking to keep up on throughout the semester/after class for excelling in this course?
- How would you recommend studying for your exams?
- Do you have any helpful tips for study habits or note taking to keep up on throughout the semester/after class for excelling in this course?
- The copious amounts of homework everyday between classes seems to be a bit much, but it seemed like you said it works great, I'm just hoping it doesn't overwhelm the students in the class and will end up trying to play catch up!
- How we can prepare well for the exams?
- Are going to give us a review for the exams?
- What do we study to get ready for quizzes?
- What would be your best suggestion for success in your class?
Detectors
- When will we go over the detectors you mentioned?
- With regarding traffic systems, mainly how we will learn about the "detector" device and its role in the whole system?
Comments on Class 03
- I thought the team agreement was a very good thing to do there have been many classes where I wish we would have ha these.
- The most meaningful to me is how you are directing the class and making it interesting.
- One thing in today's class that I found most meaningful was creating the agreement in our groups. It is important to establish guidelines within our group in order to have an effective group. Now that the agreement is signed, we can do a better job of holding one another accountable to our own expectations as a group.
- I found the most valuable part of this lab was the team agreement, it set the expectations for the group so everyone knows what to expect of one another.
- One thing i thought was important was looking at how we should do the simulation and compare it to the real world.
- The one thing that was most meaningful to me today was team collaboration and communicating effectively.
- Of all of the activities we completed today, the most meaningful thing to me was the team agreement. Team projects are a huge part of this class as I have heard and it is important that we follow along with what we agreed upon. The key to success is efficiency and it can be hard sometimes to be efficient in a group of strangers. The agreements we made are a big deal and I think it was the most important thing we did today.
- The one point I found to be most meaningful was the Team Agreement. I felt like this allowed our group to really plan out how we wanted to work together and get a better idea of how to work in a group. It gave me a sense of reassurance in my group and that we will work well together.
- The most meaningful thing for me this class period was watching and learning about the simulation. That seems to be a very useful tool in the transportation field and I am looking forward to using it in this class.
- One point with the reading in the text book is how to reflect with you team constructively, and productively so that we are all moving forward. I remember seeing the action in and action on, and how it described reflecting during the process of the project and reflecting after the project to improve the next one. I think its important to have time to reflect on the work that has been done and have time to talk about what worked, how everything ran. Thoroughly reflecting and taking the time to talk with your group about the project after its done, gives you time to encourage each other, give suggestions on how to fix things that didn't go as planned, and will help everyone be a better teammate in there next group work project. This reflection time gives us a chance to become better leaders and teammates rather than just cramming through the next project and screwing up again and again, without reflection time.
- The part that I liked most about class was when we went around and each group said what they thought was the most important parts of their reading. I learned some valuable things which I will try to apply to my group.
- The most meaningful part of class was having a group discussion on the expectations of teamwork. Teamwork is incredibly important to success not only as a civil engineer, but throughout many aspects of life.
- The thing that stuck out the most to me today was watching the video that has the SIM and the recording next to each other. I am really interesting to work with the SIM and learn more about it.
- I found it very interesting how much thought was put into the group project. I have never been someone that has enjoyed group projects however I do think that the lessons on how to make a group project more effective will benefit me the rest of my life.
- I believe that the most meaningful thing that I learned today was about getting to know the strengths and weaknesses of your group members before starting tasks or projects. It's important to know how everyone works best, and how to utilize each skill.
- I would say that the one point that was meaningful to me was seeing how well the simulation meshed up with actual traffic flows and behavior. I’m excited to learn more about the simulation and study how users behave at different intersections.
- I think the point from today's lesson that was most meaningful to me was creating a contract of sorts with my group. I think that this will be very useful throughout the course of the semester in assuring that our group will be able to work together well and get our work done efficiently and with good quality.
- Most importing thing today I learned that, how you can improve your teamwork ability. It's all about communication, organizing, and treating everyone equal, will lead to a successful team.
Question from Class 09 (2015.09.14)
1. How is it determined that an intersection will follow the actuated timing system discussed in class today instead of using a different timing system for the intersection?
6. What happens to the detector during yellow. Does it recognize a car as arriving at the intersection and start the minimum green time for opposing direction or does it just ignore the car and start the timer when the next car arrives.
7. When you have a control system do you use all the three options at once. For example use min green max green and passage timer?
1. How is it determined that an intersection will follow the actuated timing system discussed in class today instead of using a different timing system for the intersection?
- Actuated control systems are used when traffic demand varies from one cycle to the next. Of the 17 signalized intersections in Moscow, 10 operate with actuated control. Pretimed control is used most often in downtown areas where demand is generally constant and coordination from one signal to the next is desired.
- The maximum green timer starts when there is a call on a conflicting phase. This can be as early as the start of green. The passage timer and minimum green timer both start at the beginning of green.
- The purpose of the passage timer is to determine when a gap of a given size has occurred (corresponding to the end of the queue that built up during red). It becomes active at the beginning of green. It maintains its original value until the call is dropped (the detection zone becomes empty) but as long as it doesn't time down to zero it can be reset when another vehicle enters the detection zone.
- The passage time is determined based on the maximum allowable headway (MAH), or the maximum headway that we will tolerate between vehicles departing from the intersection. The MAH is usually set to the value of the saturation headway (2.0-2.5 s). The passage time is set based on the MAH in conjunction with the detection zone length and approach speed.
- The answer to your question is yes: as long as there is no call on a conflicting phase the active phase will remain green. There are, of course, exceptions to this but these involve more advanced timing processes that we won't cover during this class.
6. What happens to the detector during yellow. Does it recognize a car as arriving at the intersection and start the minimum green time for opposing direction or does it just ignore the car and start the timer when the next car arrives.
- Once the yellow begins to time, the intersection is locked into a fixed process. The yellow timer times and then the red clearance timer times. Calls continue to be received via the detectors during yellow and red clearance and they are processed for service in the order dictated by the phasing plan (as described by the ring barrier diagram). So calls received during yellow and red clearance are "remembered".
7. When you have a control system do you use all the three options at once. For example use min green max green and passage timer?
- All three timers are part of the basic actuated control process. At the beginning of green for a phase, the minimum green timer and the passage timer processes begin. If/when a call on the conflicting phase is received, the maximum green timer process begins. So, all three are involved, just evoked as a result of different events.