Assignment 01 - "Organizing" the HCM 2010
Skim the four volumes of the HCM 2010, particularly the various tables of contents in each of the volumes. Prepare a bullet list of the chapters that you consider to be key references that are most important to what you understand are the objectives of this class. Include a brief summary of each chapter. This list and summary should be saved in a MS Word document and submitted to me by email by 900 am on Wednesday, January 21st. We will discuss the organization of the HCM as part of that class so bring a copy of your work to class.
Skim the four volumes of the HCM 2010, particularly the various tables of contents in each of the volumes. Prepare a bullet list of the chapters that you consider to be key references that are most important to what you understand are the objectives of this class. Include a brief summary of each chapter. This list and summary should be saved in a MS Word document and submitted to me by email by 900 am on Wednesday, January 21st. We will discuss the organization of the HCM as part of that class so bring a copy of your work to class.
Assignment 02 - Field Observations at an All-Way Stop-Controlled Intersections
During the next two weeks of class, we will be studying the operation of all-way stop-controlled (AWSC) intersections. One of the best methods of studying the operation of this type of intersection is through field observations. Your task is to observe the intersection of 6th Street and Line Street for a period of one hour during the afternoon peak hour (between 4:15 pm and 5:15 pm). Consider the following questions as you make your observations:
Report
Prepare a one page summary of your field observations. The summary should be well organized, prepared in electronic form, and include the answers to the questions above. Be prepared to discuss your report in class. The document should be submitted to me via email by Wednesday, January 21st at 900 am.
During the next two weeks of class, we will be studying the operation of all-way stop-controlled (AWSC) intersections. One of the best methods of studying the operation of this type of intersection is through field observations. Your task is to observe the intersection of 6th Street and Line Street for a period of one hour during the afternoon peak hour (between 4:15 pm and 5:15 pm). Consider the following questions as you make your observations:
- Are there continuous queues on any of the three approaches?
- During these periods of continuous queuing, do you observe a particular order of vehicle departure from each stop line into the intersection?
- What is the [approximate] mean headway between the consecutive departure of vehicles on one approach? [Base your answer on a sample of ten headways that you record.]
- What factors do you think affect the value of this headway?
- What other observations of interest did you make?
Report
Prepare a one page summary of your field observations. The summary should be well organized, prepared in electronic form, and include the answers to the questions above. Be prepared to discuss your report in class. The document should be submitted to me via email by Wednesday, January 21st at 900 am.
Assignment 03 - Reading
- Read pp 107 through 110 (just to the point above Figure 2) of the following paper on AWSC intersections: "A Delay Model for Multiway Stop Sign Intersections" by Anthony Richardson. The paper is available on the class web site on the Resources page.
- Read pp 20-1 through 20-6 (through equation 20-4) of Chapter 20 of the HCM 2010.
- Based on these readings, prepare a brief description (no more than one page) of the model of the operation of an AWSC intersection for the case of two intersecting one-way streets . Bring your description to class and be prepared to describe this basic model.
Assignment 04 - Reading
- Read HCM 2010, pp 20-7 through 20-8, "Generalized Model for Single-Lane Sites".
- What does the term "degree of conflict" mean?
- Describe the probability of occurrence for case 2 and case 5.
- Define the term "departure headway".
- Describe in your own words the meaning of equation 20-11.
Assignment 05 - AWSC Intersection Computational Engine for Simplified Scenario #1
- Construct a computational engine (using Excel) that implements the computational steps of Simplified Scenario #1 (the intersection of two one-way streets). Provide space for the input and given data, the calculations, and the results. Use a VBA function to calculate the departure headway.
- Problem 1. Given flow rates of 300 veh/hr on the NB approach and 900 veh/hr on the WB approach. Using your computational engine, compute the departure headway and degree of saturation for each approach. Do your results seem reasonable? Why or why not?
- Problem 2. Given flow rate of 300 veh/hr on the NB approach. For the WB approach, consider a range of volumes from 0 veh/hr to 900 veh/hr in increments of 50 veh/hr. Prepare a plot showing the change in the degree of saturation (X) on the WB approach as the volume on the WB approach increases. What is the capacity of the WB approach? How does the degree of saturation on the NB approach vary as the volume on the WB approach increases? What is the degree of saturation on the NB approach when the WB approach reaches capacity?
Assignment 06 - AWSC Intersection Computational Engine for Simplified Scenario #2
The objective of this assignment is to construct a spreadsheet that computes the capacity for a four-leg single-lane approach AWSC intersection. The spreadsheet should satisfy the following requirements:
The objective of this assignment is to construct a spreadsheet that computes the capacity for a four-leg single-lane approach AWSC intersection. The spreadsheet should satisfy the following requirements:
- Accepts the flow rates on each approach as inputs.
- Computes lambda (veh/sec) for each approach.
- Computes the xS, xO, xCL, and xCR for each approach iteratively.
- Computes P[Ci] for each of the five degree of conflict cases for each approach iteratively.
- Computes the departure headway hd for each approach iteratively.
- Assume an intersection with 300 veh/hr on each approach. Use the spreadsheet to determine the capacity of the NB approach.
- What should be the sum of P[Ci] for each approach?
- What should be the maximum value of X in rows 13-16? Why?
- What could be the maximum value of X in row 27? Why?
- Your spreadsheet will have a circular reference. You may need to use the re-calculation key (F9) to obtain convergence of the departure headway.
- The likelihood of a vehicle present on an approach can never exceed one. How do you control for this in the spreadsheet tool that you are developing?
Assignment 06b - Studying the AWSC Intersection Model
- What happens when the volumes on each approach are set to 500 veh/hr? What are the results from the spreadsheet? Describe what you would observe in the field. What should X be for these volumes?
- Suppose the NB volume is 500 veh/hr and the volumes on the other approaches are zero. What is the capacity of the NB approach?
- What is the condition (DOC case) at which the intersection volume is maximum?
- Verify the five boundary conditions for this model.
- Why can X be different in rows 13-16 and in row 27?
- What is the condition at which the volume on any one approach is maximum?
Assignment 07 - Field Observation
TWSC intersections are intersections that are characterized by a major street that always has the right-of-way, and a minor street that must always stop before entering the intersection, yielding the right-of-way to all vehicles on the major street. To prepare you for this section, spent 15 minutes observing the operations of a TWSC intersection in Moscow. Prepare a set of bullet points that summarize what you observed. Be particularly aware of the driver behavior on the minor street and how it is affected by the major street operations. This assignment should be emailed to me before 900 am on January 28th.
TWSC intersections are intersections that are characterized by a major street that always has the right-of-way, and a minor street that must always stop before entering the intersection, yielding the right-of-way to all vehicles on the major street. To prepare you for this section, spent 15 minutes observing the operations of a TWSC intersection in Moscow. Prepare a set of bullet points that summarize what you observed. Be particularly aware of the driver behavior on the minor street and how it is affected by the major street operations. This assignment should be emailed to me before 900 am on January 28th.
Assignment 08 - Reading
The purpose of this assignment is to provide you with an understanding of the basic queuing model used for evaluating the performance of TWSC intersections. Be prepared to discuss this reading in class.
Reading: “The Potential Capacity of Unsignalized Intersections”, Karsten G. Baass. [Available on the class web site, “Resources” page]. [Only read pages 43 and 44, through the paragraph that ends “…and the follow-up gaps (measured in Hannover, Germany”. We will not cover the other material in the paper.
Once you have completed the reading, answer the following questions; bring your answers to class:
The purpose of this assignment is to provide you with an understanding of the basic queuing model used for evaluating the performance of TWSC intersections. Be prepared to discuss this reading in class.
Reading: “The Potential Capacity of Unsignalized Intersections”, Karsten G. Baass. [Available on the class web site, “Resources” page]. [Only read pages 43 and 44, through the paragraph that ends “…and the follow-up gaps (measured in Hannover, Germany”. We will not cover the other material in the paper.
Once you have completed the reading, answer the following questions; bring your answers to class:
- Define the following variables: Critical gap, follow up time or follow up gap, conflicting flow rate, and potential capacity.
- Write the expression that describes the probability of a gap being larger than a value of t.
- Write the expression for potential capacity developed by Grabe (and Major and Buckley), defining each of the terms in the expression.
- Write the expression for the potential capacity developed by Harders, defining each of the terms in the expression
- Explain each of the columns in Table 2.
Assignment 09 - Reading
HCM pp 19.1-19.3, 19.5-19.7
Excerpt from HCM Planning Applications Guide on TWSC Intersections (see Resources page) [not required]
HCM pp 19.1-19.3, 19.5-19.7
Excerpt from HCM Planning Applications Guide on TWSC Intersections (see Resources page) [not required]
Assignment 10 - TWSC intersection computational engine (simplified scenario #2)
Set up a computational engine that meets the following requirements for a TWSC intersection under scenario #2:
Solution
Set up a computational engine that meets the following requirements for a TWSC intersection under scenario #2:
- Accepts inputs for flow rates for movements 2, 4, and 7.
- Accepts inputs for critical headway and follow up headway for these movements.
- Computes the conflicting flow by movement, the impedance factor by movement, and the potential and movements capacities by movement.
Solution
Assignment 11 - Platoon dispersion model (reading)
To prepare for Monday's discussion on non-random arrivals at a TWSC intersection, please read the following pages of chapter 30 (Urban Street Segments: Supplemental), available as volume 4 on the HCM web site, under "Methodological Details".
To prepare for Monday's discussion on non-random arrivals at a TWSC intersection, please read the following pages of chapter 30 (Urban Street Segments: Supplemental), available as volume 4 on the HCM web site, under "Methodological Details".
- Page 30-11 (Discharge Flow Profile)
- Pages 30-12 to 30-14 (Platoon Dispersion Model)
- Pages 30-14 to 30-15 (Arrival Flow Profile)
Assignment 12 - TWSC intersection computational engine with non-random arrivals
Construct a computational engine that predicts the arrival flow at a TWSC intersection at a given distance downstream from a signalized intersection. Assume the simplified scenario of the intersection of two one-way streets serving only movements 2 and 8. The computational engine should accept the following input values:
Solution 12b
Construct a computational engine that predicts the arrival flow at a TWSC intersection at a given distance downstream from a signalized intersection. Assume the simplified scenario of the intersection of two one-way streets serving only movements 2 and 8. The computational engine should accept the following input values:
- Cycle length (60 sec), saturation flow rate (1800 veh/hr), green split time (30 sec), and red split time (30 sec) of upstream signalized intersection.
- The arrival flow rate at the signalized intersection for the TH movement that becomes movement 2 at the downstream TWSC intersection (600 veh/hr).
- The distance from the signalized intersection to the TWSC intersection (1000 ft).
- The average travel speed on the arterial (25 mi/hr).
- The time that it takes for the queue at the signalized intersection to clear at the beginning of green.
- The departure flow rate from the signalized intersection over two signal cycles.
- The arrival flow rate at the TWSC intersection over this same period of time.
- How would you check to verify that the departing flow from the signalized intersection equals the arrival flow at the downstream TWSC intersection.
- Assuming tc = 6.5 sec and tf = 4.0 sec for movement 8 at the TWSC intersection, what proportion of the hour is available for use by movement 8 vehicles?
Solution 12b
Assignment 13 - TWSC intersection simulation model (reading)
Simulating Traffic Flow at a TWSC Intersection (see Resources page)
Simulating Traffic Flow at a TWSC Intersection (see Resources page)
Assignment 14 - TWSC intersection simulation model
Objective:
Develop a stochastic, event-oriented simulation model for a two-way stop-controlled intersection that can be used to evaluate the performance of this intersection.
Assumptions:
Set up your simulation model for a simulation run that will process 200 minor street vehicles and produce the output data described above in Task 1. Assume the following data:
Run the simulation model 20 times, each time recording the required output:
Deliverable
Your deliverable is an Excel spreadsheet with your basic model and the results of the simulation.
Solution
Objective:
Develop a stochastic, event-oriented simulation model for a two-way stop-controlled intersection that can be used to evaluate the performance of this intersection.
Assumptions:
- Each approach to the intersection has one lane.
- The east-west direction is the major street, while the north-south direction is the minor street.
- Vehicle headways on both streets are assumed to be randomly distributed.
- Your simulation model should be flexible enough to handle varying flow rates on either the minor street or the major street, as well as different values of the critical headway and the follow-up headway.
- The spreadsheet should include three sections: an input section, a model computation section, and output sections for the queuing theory results and the simulation results.
- The Input Section should include the minor street flow rate (veh/hr), the major street flow rate (veh/hr), the critical headway (sec), the follow-up headway (sec), the minor street capacity (veh/hr), the mean service rate (veh/sec) for the minor street vehicles, and the mean arrival rate (veh/sec) for the minor street vehicles.
- The Model Computational Section should include the following data for each vehicle: vehicle number, randomly-generated arrival headway, the arrival time of the vehicle into the system, the service start time (time vehicle arrives into the server), a randomly-generated service time, and the service end time (time vehicle departs from the server and the system).
- The Output-Simulation Results Section should include the mean service time, the mean queue time, the mean time in the system (average delay per vehicle), the simulation time, and the minor street flow rate.
Set up your simulation model for a simulation run that will process 200 minor street vehicles and produce the output data described above in Task 1. Assume the following data:
- Mean minor street flow rate is 200 veh/hr, mean major street flow rate is 300 veh/hr
- Critical headway for minor street drivers is 6.5 sec, follow-up headway for minor street drivers is 4.0 sec
Run the simulation model 20 times, each time recording the required output:
- Mean service time
- Mean queue time
- Mean time in the system (average delay per vehicle)
- Simulation time
- Minor street flow rate.
Deliverable
Your deliverable is an Excel spreadsheet with your basic model and the results of the simulation.
Solution
Assignment 16 - Analysis of operations data at roundabouts
The purpose of this assignment is to provide you with the experience of collecting and analyzing field data for a roundabout. The videos that you will work with were made as part of NCHRP 3-65 project, in which roundabouts across the U.S. were studied and data relating to their operations were collected. You will be assigned one of these roundabouts to study, and 10 minutes of video of traffic operations from that site. You will also be given a description of the roundabout as well as several pictures of the site. Take a few minutes to view the video segment and the working paper to familiarize yourself with your intersection.
Videos
When you are ready to collect the data:
1. Start the Traffic Tracker software. If you haven't used it before, review its features and how to set up a data collection environment, collect data, and save and review an output file.
2. Identify three points for your roundabout site: the point at which vehicles enter the system, the point at which a vehicle becomes first in line in the server position, and the point at which a vehicle leaves the server and enters the intersection. You will record the times that each minor stream vehicle arrives at each of these points.
3. Identify a fourth point for each site: the conflicting point on the circle for the circulating flow. You will record the time that each circulating vehicle arrives at this conflicting point.
4. For your site, complete the following steps: (1) set up a data collection environment in Traffic Tracker, (2) collect event/time data for each of the four points described above for all of the minor stream vehicles and circulating (major stream) vehicles for a period of ten minutes, (3) save the data collection file.
5. Save the data file in an Excel spreadsheet.
After completing the data collection process, proceed with the following data analysis and presentation tasks:
1. Queuing data: Determine the queue time, service time, and total time in system for the entry approach.
2. Determine the flow rates for both conflicting flow and subject (entry) flow.
3. Prepare a queue accumulation polygon for the entry approach, showing the queue length over time.
4. Prepare a summary of the gap acceptance/rejection data, including a statistical analysis and frequency distributions.
5. Prepare an analysis of the follow up headway.
Assemble your data and conclusions into an Excel spreadsheet that includes (1) all raw data, (2) all processed data as per the list above, and (3) your analysis. Be prepared to make a 5-10 minute (informal) presentation of your process and results in class.
The purpose of this assignment is to provide you with the experience of collecting and analyzing field data for a roundabout. The videos that you will work with were made as part of NCHRP 3-65 project, in which roundabouts across the U.S. were studied and data relating to their operations were collected. You will be assigned one of these roundabouts to study, and 10 minutes of video of traffic operations from that site. You will also be given a description of the roundabout as well as several pictures of the site. Take a few minutes to view the video segment and the working paper to familiarize yourself with your intersection.
- Roundabout videos
- NCHRP 3-65 working paper 13 - site descriptions (see appendix B)
Videos
- Team 1: ME01-E2 (30 minutes)
- Team 2: MD07-E1 (12 minutes)
- Team 3: WA04 N1 (11 minutes)
When you are ready to collect the data:
1. Start the Traffic Tracker software. If you haven't used it before, review its features and how to set up a data collection environment, collect data, and save and review an output file.
2. Identify three points for your roundabout site: the point at which vehicles enter the system, the point at which a vehicle becomes first in line in the server position, and the point at which a vehicle leaves the server and enters the intersection. You will record the times that each minor stream vehicle arrives at each of these points.
3. Identify a fourth point for each site: the conflicting point on the circle for the circulating flow. You will record the time that each circulating vehicle arrives at this conflicting point.
4. For your site, complete the following steps: (1) set up a data collection environment in Traffic Tracker, (2) collect event/time data for each of the four points described above for all of the minor stream vehicles and circulating (major stream) vehicles for a period of ten minutes, (3) save the data collection file.
5. Save the data file in an Excel spreadsheet.
After completing the data collection process, proceed with the following data analysis and presentation tasks:
1. Queuing data: Determine the queue time, service time, and total time in system for the entry approach.
2. Determine the flow rates for both conflicting flow and subject (entry) flow.
3. Prepare a queue accumulation polygon for the entry approach, showing the queue length over time.
4. Prepare a summary of the gap acceptance/rejection data, including a statistical analysis and frequency distributions.
5. Prepare an analysis of the follow up headway.
Assemble your data and conclusions into an Excel spreadsheet that includes (1) all raw data, (2) all processed data as per the list above, and (3) your analysis. Be prepared to make a 5-10 minute (informal) presentation of your process and results in class.
Assignment 17
- Read pp 18.1-18.6 in the HCM 2010 for an overview of the signalized intersection methodology. Prepare an outline of the key points of this section of the HCM. List the terms and/or concepts that you think are most important.
- Read "Signalized Intersection Module Excerpt: Representing Traffic Flow at a Signalized Intersection" and "Signalized Intersection Module Excerpt: Sequencing and Controlling Movements" from the Resources page for a review of traffic flow characteristics at a signalized intersection and how movements are controlled by phases at a pretimed signalized intersection. Prepare sketches of a flow profile diagram, a cumulative vehicle diagram, and a queue accumulation polygon and label the important parts of each sketch. Prepare a sketch of a ring barrier diagram for a standard 4-leg intersection with 8 phases.
- Be prepared to discuss these readings and your notes and sketches in class.
Assignment 18
- Read "Signalized Intersection Module Excerpt: Critical Movement Analysis" from the Resources page.
- Be ready to discuss the following: key terms and concepts, the methodology, and what the methodology produces.
Assignment 19
Complete analysis of intersection sufficiency of capacity using the critical movement analysis method given the following data:
Complete analysis of intersection sufficiency of capacity using the critical movement analysis method given the following data:
- Two lanes on each approach, one exclusive LT lane and one TH lane.
- v1 = 150
- v2 = 500
- v3 = 150
- v4 = 550
- v5 = 100
- v6 = 400
- v7 = 100
- v8 = 400
- Cycle length = 80 sec
- Saturation flow rate = 1900 veh/hr/lane
- Lost time per phase = 4 sec
Assignment 20 - Reading
- Read "Signalized Intersection Module Excerpt: Uniform Delay" from the Resources page.
- Be ready to discuss (1) the uniform delay equation and (2) the graphical method for determining delay for the conditions that demand is less than capacity and greater than capacity.
Assignment 21 - Delay during oversaturated conditions
An approach to a pretimed signalized intersection has a saturation flow rate of 1700 vehicles per hour of green. The cycle length is 60 seconds and the effective red is 40 seconds. During three consecutive cycles 15, 8, and 4 vehicles arrive. The arrival pattern should be assumed to be uniform during each cycle.
Solution
An approach to a pretimed signalized intersection has a saturation flow rate of 1700 vehicles per hour of green. The cycle length is 60 seconds and the effective red is 40 seconds. During three consecutive cycles 15, 8, and 4 vehicles arrive. The arrival pattern should be assumed to be uniform during each cycle.
- Prepare a flow profile diagram, a cumulative vehicle diagram, and a queue accumulation polygon for these conditions.
- Determine the total vehicle delay and the average delay per vehicle for each cycle, and for all three cycles.
- For the queue present at the beginning of each of the three green intervals, how long would it take for each queue to clear?
- Is there sufficient capacity on capacity on this approach to serve the demand?
Solution
Assignment 22 - Reading
The purpose of this reading assignment is to prepare you to study the method used to calculate saturation flow rates for permitted LT from both exclusive LT lanes and shared LT/TH lanes. The HCM methods for these cases are complex and will require some work on your part to master. I would suggest that you carefully study the QAPs for both of these cases. Here are the relevant sections from Chapter 31 of the HCM 2010 that you need to read before our next class:
The purpose of this reading assignment is to prepare you to study the method used to calculate saturation flow rates for permitted LT from both exclusive LT lanes and shared LT/TH lanes. The HCM methods for these cases are complex and will require some work on your part to master. I would suggest that you carefully study the QAPs for both of these cases. Here are the relevant sections from Chapter 31 of the HCM 2010 that you need to read before our next class:
- QAP concepts (Introduction, Concepts): pp 31.48-31.49
- Step 1. Determine permitted LT green time: pp 31.51-31.53
- Step 2. Determine time before first LT vehicle arrives: pp 31.53-31.54
- Step 3. Determine permitted LT saturation flow rate: pp 31.54.31.55
- QAPs for permitted LTs from exclusive lane and from shared lane: Exhibit 31.17 ( p 31.61) and Exhibit 31.18 (p 31.62)
Assignment 23 - Permitted LT studies
The purpose of this assignment is to study the effects that various input values have on the predicted values of the time for the opposing queue to clear and the time for the first subject LT vehicle to arrive at the intersection. Use an Excel spreadsheet to complete these studies. Then answer the questions about your results.
Assume that the cycle length is 60 sec, the green ratio is 0.5, the saturation flow rate is 1900 veh/hr, the base opposing TH volume is 700 veh/hr and the subject shared lane flows are 50 veh/hr for the LT movement and 50 veh/hr for the TH movement.
Prepare charts that show:
Answer the following questions:
The purpose of this assignment is to study the effects that various input values have on the predicted values of the time for the opposing queue to clear and the time for the first subject LT vehicle to arrive at the intersection. Use an Excel spreadsheet to complete these studies. Then answer the questions about your results.
Assume that the cycle length is 60 sec, the green ratio is 0.5, the saturation flow rate is 1900 veh/hr, the base opposing TH volume is 700 veh/hr and the subject shared lane flows are 50 veh/hr for the LT movement and 50 veh/hr for the TH movement.
Prepare charts that show:
- The opposing queue service time gso as a function of the opposing TH volume (with a range from 0 to 1000 veh/hr).
- The time for the first subject LT vehicle to arrive after the start of green gf as a function of the subject LT volume (with a range from 0 to 800 veh/hr).
Answer the following questions:
- Comment on the predicted value of the queue service time when the opposing TH volume is 1000 veh/hr.
- At what subject LT volume does the arrival of the first LT vehicle occur almost immediately after the start of green?
- Briefly summarize what you've learned in reviewing these two charts about the operation of permitted LTs.
Assignment 24 - Reading
HCM 2010
HCM 2010
- Chapter 18, determining uniform delay (pp 18.46-18.48)
- Chapter 30, predicting the arrival flow profile (pp 30.11-30.15)
Assignment 25 - Predicting delay when arrivals are non-uniform
The purpose of this assignment is to study how arrival patterns affect the delay at a signalized intersection. Your work for each task should be clearly documented and the spreadsheet should be clearly organized so that it can be easily followed. Use VBA functions as needed. Assume the following input data:
The purpose of this assignment is to study how arrival patterns affect the delay at a signalized intersection. Your work for each task should be clearly documented and the spreadsheet should be clearly organized so that it can be easily followed. Use VBA functions as needed. Assume the following input data:
For both intersections:
|
For upstream intersection:
|
For downstream intersection:
|
Other data:
|
Tasks
Task 1. Calculate the departure flow profile for the upstream intersection and the arrival flow profile for the downstream intersection showing 1 sec time steps over a four cycle period.
Task 2. Prepare plots of both flow profiles that you calculated in task 1. The plots should also show the four green and red time intervals over time.
Task 3. For each time step, beginning with the start of the second red interval and continuing for one complete cycle, calculate the queue length. Based on these data, prepare a queue accumulation polygon for this cycle.
Task 4. For this same cycle, calculate the total and average delays.
Task 5. For this same cycle, and for a range of offsets from 0 to 60 sec in intervals of 5 sec, show how average delay varies as a function of the offset.
[Don't do tasks 6 and 7]
Task 6. Are your results from task 5 consistent with the queue accumulation polygon for three offset values (that you select).
Task 7. How do your predictions of average delay for varying offsets compare with your calculated average delay assuming uniform arrivals?
Solution
Task 1. Calculate the departure flow profile for the upstream intersection and the arrival flow profile for the downstream intersection showing 1 sec time steps over a four cycle period.
Task 2. Prepare plots of both flow profiles that you calculated in task 1. The plots should also show the four green and red time intervals over time.
Task 3. For each time step, beginning with the start of the second red interval and continuing for one complete cycle, calculate the queue length. Based on these data, prepare a queue accumulation polygon for this cycle.
Task 4. For this same cycle, calculate the total and average delays.
Task 5. For this same cycle, and for a range of offsets from 0 to 60 sec in intervals of 5 sec, show how average delay varies as a function of the offset.
[Don't do tasks 6 and 7]
Task 6. Are your results from task 5 consistent with the queue accumulation polygon for three offset values (that you select).
Task 7. How do your predictions of average delay for varying offsets compare with your calculated average delay assuming uniform arrivals?
Solution
Assignment 26 - Reading
The purpose of this assignment is to learn the fundamental elements of the green time prediction process for the signalized intersection method of the HCM 2010. There are two such prediction processes, one for pretimed control and the other for actuated control. The actuated control method is especially complicated and will require careful study on your part. We will start this process through readings in chapter 31 and documenting the parameters that are used in these methods. Note that the actuated control method is written to cover all possible conditions, more than are needed for most analyses. Our task is to sort through this complexity and ask: what are the basic elements of the method required for our simplified scenario (the intersection of two one-way streets, one lane per approach, TH movements only).
Task 1. Read the sections in the HCM 2010 on predicting green time for pretimed control (pp 31.37-31.40) and actuated control (pp 31.10-31.30).
Task 2. List and define (as best you can) the parameters required for each method to predict green time duration. In addition to the sections listed above, consult the input data table in chapter 18 (Exhibit 18.6, p 18.8).
Task 3. List and define the parameters that are intermediate calculations or results for each method.
The purpose of this assignment is to learn the fundamental elements of the green time prediction process for the signalized intersection method of the HCM 2010. There are two such prediction processes, one for pretimed control and the other for actuated control. The actuated control method is especially complicated and will require careful study on your part. We will start this process through readings in chapter 31 and documenting the parameters that are used in these methods. Note that the actuated control method is written to cover all possible conditions, more than are needed for most analyses. Our task is to sort through this complexity and ask: what are the basic elements of the method required for our simplified scenario (the intersection of two one-way streets, one lane per approach, TH movements only).
Task 1. Read the sections in the HCM 2010 on predicting green time for pretimed control (pp 31.37-31.40) and actuated control (pp 31.10-31.30).
Task 2. List and define (as best you can) the parameters required for each method to predict green time duration. In addition to the sections listed above, consult the input data table in chapter 18 (Exhibit 18.6, p 18.8).
Task 3. List and define the parameters that are intermediate calculations or results for each method.
Assignment 27 - Phase Duration Estimation for Actuated Control
The purpose of this assignment is to set up a computational engine to predict phase duration for a simple system (two intersecting one-way streets) under actuated control.
Task 1. Document all parameters, both input and calculated, required for this procedure under the simplified conditions for this scenario. This can be handwritten.
Task 2. Document the calculation sequence for phase duration in flow chart form. This can be handwritten.
Task 3. Create a spreadsheet with space for the input parameters that you identified in task 1. The space should include the parameter name, the value, and the units.
Task 4. Add to the spreadsheet the calculated parameters that you identified in task 1, again including the parameter name, the value, and the units. Use VBA functions as needed for the calculated parameters.
The purpose of this assignment is to set up a computational engine to predict phase duration for a simple system (two intersecting one-way streets) under actuated control.
Task 1. Document all parameters, both input and calculated, required for this procedure under the simplified conditions for this scenario. This can be handwritten.
Task 2. Document the calculation sequence for phase duration in flow chart form. This can be handwritten.
Task 3. Create a spreadsheet with space for the input parameters that you identified in task 1. The space should include the parameter name, the value, and the units.
Task 4. Add to the spreadsheet the calculated parameters that you identified in task 1, again including the parameter name, the value, and the units. Use VBA functions as needed for the calculated parameters.
Assignment 28 - Phase Duration Estimation for Actuated Control
The purpose of this assignment is to enhance the computational engine that you developed for Assignment 27 and directly calculate the phase durations for the two approaches (iteratively). Your completed computational engine should accept the input parameters (as per task 3 in Assignment 27) and calculate the required values for each of the two phases:
Solution
The purpose of this assignment is to enhance the computational engine that you developed for Assignment 27 and directly calculate the phase durations for the two approaches (iteratively). Your completed computational engine should accept the input parameters (as per task 3 in Assignment 27) and calculate the required values for each of the two phases:
- queue service time, gs
- green extension time, ge
- Displayed green, G
- Phase duration, Dp
- Cycle length, C
Solution
Assignment 29 - Model Checking
The purpose of this assignment is to perform several "reasonableness" checks using the model that you have developed for actuated signal control. List three conditions that you know have to be satisfied by the model. Verify that these three conditions are met. Discuss your results.
The purpose of this assignment is to perform several "reasonableness" checks using the model that you have developed for actuated signal control. List three conditions that you know have to be satisfied by the model. Verify that these three conditions are met. Discuss your results.
Assignment 30 - Parametric Analysis
The purpose of this assignment is to conduct a parametric analysis of the actuated signal control model. Clearly define your input assumptions for each of the following studies. Focus your work on one approach only, holding the demand volume or other parameters constant on the other approach.
Solution
The purpose of this assignment is to conduct a parametric analysis of the actuated signal control model. Clearly define your input assumptions for each of the following studies. Focus your work on one approach only, holding the demand volume or other parameters constant on the other approach.
- For conditions in which demand is less than capacity, construct a plot showing the variation of uniform delay with demand. Provide a brief discussion of your results.
- Study the effect of demand volume on the probability of a phase call. Provide a brief discussion of your results.
- Study the effect of demand volume on the green extension time ge. Provide a brief discussion of your results.
Solution
Assignment 31 - HCS and AWSC Intersection Analysis
Solution
Solution (student)
- Review pages 20.9 - 20.17 in HCM 2010. This section covers the basic AWSC intersection methodology for automobiles.
- Use the HCS to verify the results for Example Problem #1 (pp 20.22 - 20.26). Prepare an interpretation of the results: what is the meaning of the results for a traffic engineer?
- Select one output parameter from the HCS analysis and conduct a parametric or sensitivity analysis based on one input parameter. Present your results in a spreadsheet.
Solution
Solution (student)
Assignment 32 - Reading
Read the paper "Saturation Headways at Stop-Controlled Intersections", Transportation Research Record 1457. See Resources page under AWSC Intersections.
Read the paper "Saturation Headways at Stop-Controlled Intersections", Transportation Research Record 1457. See Resources page under AWSC Intersections.
Assignment 33 - Reading
Review the TWSC intersection methodology in the HCM 2010. Prepare a list any questions that you have on the reading.
Review the TWSC intersection methodology in the HCM 2010. Prepare a list any questions that you have on the reading.
- Level of service (pp 19.1-19.2)
- Input data required (pp 19.2-19.3)
- Methodology (pp 19.5-19.7 and exhibit 19.4 on p 19.8)
Assignment 34 - TWSC Intersection Application
Use the HCS to solve example problem 1 (pp 19.43-19.49). Verify each step of the HCM results with the HCS output. Identify any discrepancies or parts of the calculation that you don't understand. Prepare a 2-3 paragraph interpretation of the results.
Use the HCS to solve example problem 1 (pp 19.43-19.49). Verify each step of the HCM results with the HCS output. Identify any discrepancies or parts of the calculation that you don't understand. Prepare a 2-3 paragraph interpretation of the results.
Assignment 35 - TWSC Intersection Studies
You will be assigned a base intersection configuration with traffic volumes. You will also be assigned one of the following special cases to study. Your tasks are to:
Base case conditions:
Special cases:
#1: Curb median on major street (Ben)
You will be assigned a base intersection configuration with traffic volumes. You will also be assigned one of the following special cases to study. Your tasks are to:
- Run the base case conditions and record the delay and LOS for each lane and approach.
- Run the special case and record the delay and LOS for each lane and approach.
- Conduct a sensitivity analysis using one input parameter for your special case and record the delay and LOS for each lane and approach.
- Present and interpret the results of your analysis.
- Be able to explain the model that covers your special case.
Base case conditions:
- One lane per movement
- EB LT = 75
- EB TH = 175
- WB LT = 125
- WB TH = 250
- NB LT = 25
- NB TH = 150
- SB LT = 25
- SB TH = 175
Special cases:
#1: Curb median on major street (Ben)
- storage spaces = 1
- Reference: pp 19.22-19.23, 19.24-19.25
- Both directions, Distance = 500 ft, Speed = 25 m/hr, C = 60 sec, Progressed volume = 250, Arrival type = 3, Green =30 sec
- Reference: pp 19.17-19.18
- One shared lane on both NB and SB approaches
- Reference: pp 19.25
- One shared lane on both EB and WB approaches
- Reference: pp 19.20-19.21
- storage spaces = 3, LT vol = 25, TH vol = 100, RT vol = 50
- Reference: pp 19.25-19.27
- Peds crossing major = 25 each, crossing minor = 25 each
- Reference: pp 19.10-19.11
- storage spaces = 3
- Reference: pp 19.22-19.23, 19.24-19.25
Assignment 36 - Reading (Signalized Intersections)
Read the following sections in chapter 18 to prepare you for using the HCS signals module:
Read the following sections in chapter 18 to prepare you for using the HCS signals module:
- pp 18.1-18.8
- pp 18.31-18.32
Assignment 37 - Signalized Intersection Analysis - Pretimed Control
The handout provides given traffic flow and intersection geometry data. Assuming pretimed control and a cycle length of 90 seconds, use the HCS to complete an operational analysis of the intersection. Study the detailed output using both the "Signals Text Report" and the "Intermediate Report". Prepare a brief calculation narrative (no more than one page bullet list or summary) that describes the steps used to produce the final analysis. Be ready to discuss your narrative on Friday.
The handout provides given traffic flow and intersection geometry data. Assuming pretimed control and a cycle length of 90 seconds, use the HCS to complete an operational analysis of the intersection. Study the detailed output using both the "Signals Text Report" and the "Intermediate Report". Prepare a brief calculation narrative (no more than one page bullet list or summary) that describes the steps used to produce the final analysis. Be ready to discuss your narrative on Friday.
Assignment 38 - Signalized Intersection Analysis - Actuated Control
Using the same data given in Assignment 37, prepare an HCM operational analysis assuming actuated control. As before, study the detailed output using both the "Signals Text Report" and the "Intermediate Report". Prepare a brief calculation narrative (no more than one page bullet list or summary) that describes the steps used to produce the final analysis. Be ready to discuss your narrative on Monday.
Using the same data given in Assignment 37, prepare an HCM operational analysis assuming actuated control. As before, study the detailed output using both the "Signals Text Report" and the "Intermediate Report". Prepare a brief calculation narrative (no more than one page bullet list or summary) that describes the steps used to produce the final analysis. Be ready to discuss your narrative on Monday.
Assignment 39 - Signalized Intersection Analysis - Adjustment Factors
Saturation flow rate is one of the most important parameters using to estimate the capacity of a signalized intersection. The HCM describes a series of adjustment factors that are used to modify the base saturation flow rate as part of an operational analysis. Read pp 18.35-18.39 in the HCM 2010 to learn more about these adjustment factors. Pick two of the adjustment factors and prepare a description of an experiment that you could run using the HCS to understand more of the impact of these two factors on the predicted saturation flow rate and on the final predicted performance.
Saturation flow rate is one of the most important parameters using to estimate the capacity of a signalized intersection. The HCM describes a series of adjustment factors that are used to modify the base saturation flow rate as part of an operational analysis. Read pp 18.35-18.39 in the HCM 2010 to learn more about these adjustment factors. Pick two of the adjustment factors and prepare a description of an experiment that you could run using the HCS to understand more of the impact of these two factors on the predicted saturation flow rate and on the final predicted performance.
Assignment 40 - Signalized Intersection Analysis - Adjustment Factor Analysis
Pick one of the two factors that you identified in Assignment 39. Prepare a sensitivity analysis for one of these factors by determining its effect on the saturation flow rate over a reasonable range of values. Prepare a plot of the results of the sensitivity analysis. Turn in your results in an Excel spreadsheet.
Pick one of the two factors that you identified in Assignment 39. Prepare a sensitivity analysis for one of these factors by determining its effect on the saturation flow rate over a reasonable range of values. Prepare a plot of the results of the sensitivity analysis. Turn in your results in an Excel spreadsheet.
Assignment 41 - Signalized Intersection Analysis - Left Turn Phasing Study
Data are given in the attached file. Assume default values from HCS for all other data. Complete an analysis of both protected and permitted left turn phasing (not protected plus permitted phasing) using the HCS. Review the computational steps for both analyses and identify any questions that you have.
Data are given in the attached file. Assume default values from HCS for all other data. Complete an analysis of both protected and permitted left turn phasing (not protected plus permitted phasing) using the HCS. Review the computational steps for both analyses and identify any questions that you have.
Assignment 42 - Signalized Intersection Analysis - Effect on Arrival Patterns on Delay
Using the HCS, construct a two intersection signalized intersection system with the following characteristics:
Using the HCS, construct a two intersection signalized intersection system with the following characteristics:
- Pretimed
- TH movements only on each of the four approaches with volumes of 400 veh/hr on each approach
- Intersection spacing of 500 ft
- C = 90 sec
- All other HCS defaults
Assignment 43 - HCMAG Presentations
The purpose of this assignment is to review one case study from the HCM Applications Guide and make a presentation on your findings. The content of the HCMAG will serve as an example for the final project (Assignment 44) that you will complete by the end of the semester. For this current assignment:
The purpose of this assignment is to review one case study from the HCM Applications Guide and make a presentation on your findings. The content of the HCMAG will serve as an example for the final project (Assignment 44) that you will complete by the end of the semester. For this current assignment:
- Read the HCMAG Research Results Digest from the Resources page.
- Read the Introduction chapter from the HCMAG.
- Read the case study from the HCMAG that you have been assigned.
- Identify the primary problem that the case study is intended to address. Identify the scope of the analysis, the goals of the evaluation or analysis, and the specific problems that are used to address or illustrate the original problem.
- Through discussions with your partner, prepare a list of things that you learned about traffic analysis as a result of reading this case study.
- Based on items 2 and 3, prepare a presentation (10-15 minutes duration) that you will make to the rest of the class (with a partner) on Friday, April 24th. The presentation should show your understanding of the case study and what it is intended to accomplish. It should also include what you have learned about conducting an operational analysis of an intersection.
- Case study 1. US 95 corridor (Arman, Ben)
- Case study 2. Route 146 corridor (Brett, Marvin, Maged)
- Case study 5. Museum Road (Riannon, Kushel)
Assignment 44 - Project
The purpose of this assignment is to give you the experience of completing an analysis of traffic operations using the methods of the HCM, the HCS software tool, and the insights and methods from the HCM Applications Guide. Your work will include a statement of the problem, the scope of the problem including the key intersection and the larger system of which it is a part, a list of the technical issues that could be addressed by one or more HCM methods or models, a discussion of each of these issues, and the results that are produced with the application of the particular HCM method. This work will culminate with a final report and presentation during the final examination period on Tuesday, May 12th. You will be assigned a vacant parcel of land within the city of Moscow as the basis for your project.
Task 1. Review the parcel of land that you have been assigned using online maps and by visiting the site. Prepare a study proposal that describes the site that you have been assigned and a traffic problem that you create that you will address in your final report. The proposal should also include the scope of the problem that you will address (including your initial perception of the key issues that are involved) and the relevant HCM models or methods that you will use. It should include the list of works tasks that you will address and complete. It should also include three issues that you will address as per the approach taken by the HCMAG. What you learn from reading the HCMAG should also be used to inform and structure your proposal. The proposal should be either two or three pages in length. You may work with me as you create this problem. This proposal should be emailed to me by Monday, April 27th at 800 am. Bring three printed copies of your proposal to class on April 27th.
Task 2. Complete all HCS work and summarize these results in a set of Excel tables. Be prepared to share your work with the class using no more than 5 PowerPoint slides in class on Monday, May 4th. Your Excel worksheet and PowerPoint slides should be emailed to me by 800 am on May 4th.
Task 3. Complete your draft report by Friday, May 8th. Be prepared to discuss your draft with me during class and identify any remaining issues to complete. The draft report should be emailed to me by 800 am on May 8th.
Task 4. Complete the final report and presentation by Tuesday, May 12th. You will make a 15 minute presentation of your work during the final examination period. The final report should be no more than 10 pages in length. The deliverables will be the final report (Word document) and presentation (including PowerPoint slides) and must be emailed to me in a zip folder by Tuesday, May 12th at 800 am.
Your report and presentation should be based on the structure of the HCMAG and should include the following sections:
Your report and presentation will be graded based on the following factors:
Assigned case study locations:
Common Questions:
Where do we get the traffic volumes?
The purpose of this assignment is to give you the experience of completing an analysis of traffic operations using the methods of the HCM, the HCS software tool, and the insights and methods from the HCM Applications Guide. Your work will include a statement of the problem, the scope of the problem including the key intersection and the larger system of which it is a part, a list of the technical issues that could be addressed by one or more HCM methods or models, a discussion of each of these issues, and the results that are produced with the application of the particular HCM method. This work will culminate with a final report and presentation during the final examination period on Tuesday, May 12th. You will be assigned a vacant parcel of land within the city of Moscow as the basis for your project.
Task 1. Review the parcel of land that you have been assigned using online maps and by visiting the site. Prepare a study proposal that describes the site that you have been assigned and a traffic problem that you create that you will address in your final report. The proposal should also include the scope of the problem that you will address (including your initial perception of the key issues that are involved) and the relevant HCM models or methods that you will use. It should include the list of works tasks that you will address and complete. It should also include three issues that you will address as per the approach taken by the HCMAG. What you learn from reading the HCMAG should also be used to inform and structure your proposal. The proposal should be either two or three pages in length. You may work with me as you create this problem. This proposal should be emailed to me by Monday, April 27th at 800 am. Bring three printed copies of your proposal to class on April 27th.
Task 2. Complete all HCS work and summarize these results in a set of Excel tables. Be prepared to share your work with the class using no more than 5 PowerPoint slides in class on Monday, May 4th. Your Excel worksheet and PowerPoint slides should be emailed to me by 800 am on May 4th.
Task 3. Complete your draft report by Friday, May 8th. Be prepared to discuss your draft with me during class and identify any remaining issues to complete. The draft report should be emailed to me by 800 am on May 8th.
Task 4. Complete the final report and presentation by Tuesday, May 12th. You will make a 15 minute presentation of your work during the final examination period. The final report should be no more than 10 pages in length. The deliverables will be the final report (Word document) and presentation (including PowerPoint slides) and must be emailed to me in a zip folder by Tuesday, May 12th at 800 am.
Your report and presentation should be based on the structure of the HCMAG and should include the following sections:
- Overview (what the problem is about, issues that will be explored)
- Introduction (description of area and facility)
- Getting Started (scope, stakeholders, goals and objectives, what analyses to perform)
- Problems (how to address various aspects of the problem using HCM methods)
Your report and presentation will be graded based on the following factors:
- Description of the problem that you created. (5 points)
- Your approach to the analysis of traffic operations as described in the report. (5 points)
- How well you included insights from the HCM Applications Guide in approaching the analysis of traffic operations. (10 points)
- The correct and insightful use of the HCM and HCS. (10 points)
- Your interpretation of the HCS results in addressing your problem. (10 points)
- The quality of your report including organization and writing. (15 points)
- The quality of your presentation. (15 points)
Assigned case study locations:
- Parcel: NE Corner of Rosauers Parking Lot. Primary intersection: US 95/D Street. (Arman)
- Parcel: Empty land near US 95 and Rodeo Dr. Primary intersection: US 95/Rodeo Dr (Maged)
- Parcel: Vacant lot at Jackson and 3rd. Primary intersection: Jackson/3rd (Kushal)
- Parcel: Parcel near Farm Rd and A Street. Primary intersection: SH 8/Farm Rd. (Marvin)
- Parcel: Undeveloped land at SH 8 east of Mt. View. Primary intersection: SH 8/Mt View. (Brett)
- Parcel: Parcel near US 95 and Sweet, including Dominos Pizza. Primary intersection: US 95/Sweet. (Ben)
- Parcel: Vacant land near 8th St (College St) and Jackson St. Primary intersection: Jackson/College. (Riannon)
Common Questions:
Where do we get the traffic volumes?
- You will create any data that you need for both existing and future conditions.
- You will create the scenario that describes the development and its characteristics that you believe to be appropriate to the study location that you have been assigned.
- Mostly no. Your focus should be on the existing geometric layout of the site. However, if the site does not currently include driveway access from a street, you will need to identify where this access point is. Again, you do not need to do any geometric design for this project.
- You should do this by having at least one slide in your presentation that addresses this specifically. But you don't (and probably can't) address this in your report.