Preparation for Exam #1 - 13 March 2015
As you prepare for this examination, review the list below. The examination will be based on the knowledge, skills, and abilities included in this list for AWSC intersections, TWSC intersections, and signalized intersections. The operation of roundabouts will not be covered on the examination.
As you prepare for this examination, review the list below. The examination will be based on the knowledge, skills, and abilities included in this list for AWSC intersections, TWSC intersections, and signalized intersections. The operation of roundabouts will not be covered on the examination.
AWSC Intersections
- Describe the concepts that form the basic capacity model including degree of conflict and the interaction between traffic streams.
- Define and describe the driver behavior parameter: saturation headway for each degree of conflict case.
- Apply and interpret the expected value of the departure headway for one approach.
- Interpret the results of a capacity analysis for an AWSC intersection with one lane on each of four approaches.
TWSC Intersections
- Describe the concepts that make up the basic gap acceptance model.
- Interpret the gap acceptance model and the parameters that constitute the model.
- Define, describe, and apply the driver behavior parameters: critical headway and follow up headway.
- Describe and interpret the events that are used to construct gap acceptance and rejection data.
- Define and apply the concept of Impedance.
- Interpret the results of a capacity analysis for a TWSC intersection with one major street TH movement, one major street LT movement, and one minor street LT movement.
Signalized Intersections
- Describe and apply the basic capacity concept: the product of saturation flow rate and green ratio.
- Apply and interpret a critical movement analysis for a signalized intersection with two lanes on each approach (one LT lane and one TH lane) with protected LT phasing.
- Apply and interpret the calculation of delay assuming either uniform arrivals or platooned arrivals.
- Apply and interpret a capacity analysis for permitted LTs from an exclusive LT lane.
- Construct and interpret a queue accumulation polygon for various arrival and departure patterns.
- Explain and interpret the calculation of queue service time and green extension time for one approach of a signalized intersection operating under actuated signal control.
Examination #2 - Due 17 April 2015
The purpose of this examination is to test your ability to apply the HCM methods to the problem of intersection control. Each of you will be given a problem with the same basic geometry but with different traffic volumes, and assumes two-way stop control. Your problem is to conduct a set of analyses to determine whether the existing stop sign control should be retained or whether the control should be changed to all-way stop control or signal control. To reach your decision, the analysis should include the following cases:
Once you have completed your analysis, you will answer a set of nine questions. Your examination will be graded on the following criteria:
You need to submit a Word document (exam answers) and an Excel spreadsheet (results and analysis) to me in a zipped folder via email by Friday, April 17th, at 1130 pm (as noted by the time stamp in your email). Late submissions will not be accepted. The examination and all relevant data will be distributed to you on Friday, April 10th.
The purpose of this examination is to test your ability to apply the HCM methods to the problem of intersection control. Each of you will be given a problem with the same basic geometry but with different traffic volumes, and assumes two-way stop control. Your problem is to conduct a set of analyses to determine whether the existing stop sign control should be retained or whether the control should be changed to all-way stop control or signal control. To reach your decision, the analysis should include the following cases:
- Base case (TWSC intersection)
- Base case volume with all-way stop-control and signal control
- Future volumes for all three control types
Once you have completed your analysis, you will answer a set of nine questions. Your examination will be graded on the following criteria:
- Quality of presentation of results and conclusions (20 points)
- Writing quality (20 points)
- Quality of the analysis including completeness, accuracy, appropriate use of software, and interpretation of software results (60 points)
You need to submit a Word document (exam answers) and an Excel spreadsheet (results and analysis) to me in a zipped folder via email by Friday, April 17th, at 1130 pm (as noted by the time stamp in your email). Late submissions will not be accepted. The examination and all relevant data will be distributed to you on Friday, April 10th.
Examination #2 - Clarifications
Problems 2 and 3: Consider only the future volumes in answering these two problems.
Consider the following precision levels for each of the three performance measures:
Questions from three students:
(1) In exam#2 during AWSC HCS analysis, HCS doesn't allow us to enter more than 2 Lane on each approach and the problem in Exam is having 3 Lane on Major Street. So should we Remove 1 Thru Lane from Major Street and go ahead with Analysis or do the calculations as per HCM methodology ?
(2) I can't get the HCS AWSC to allow three approaches. Do you want us to change the geometry?
(3) I tried to put the same lane configuration of TWSC in AWSC in HCS. But in quick entry, its not taking the lane configuration I wanted to put.
Problems 2 and 3: Consider only the future volumes in answering these two problems.
Consider the following precision levels for each of the three performance measures:
- Delay to the nearest second.
- Volume to capacity ratio to the nearest tenth.
- Queue length to the nearest tenth of a vehicle.
Questions from three students:
(1) In exam#2 during AWSC HCS analysis, HCS doesn't allow us to enter more than 2 Lane on each approach and the problem in Exam is having 3 Lane on Major Street. So should we Remove 1 Thru Lane from Major Street and go ahead with Analysis or do the calculations as per HCM methodology ?
(2) I can't get the HCS AWSC to allow three approaches. Do you want us to change the geometry?
(3) I tried to put the same lane configuration of TWSC in AWSC in HCS. But in quick entry, its not taking the lane configuration I wanted to put.
- Clarification: Remember the wording of the question. Your task is to apply the model, knowing its limitations, in a way that will give you a reasonable answer. Don't make any changes in the given geometry.