Case Study 1 Problem 3 Styner/Lauder Intersection Moscow, Idaho

1. Case Study 1Problem 3Styner/Lauder IntersectionMoscow, Idaho

2. Problem 3 Event Traffic Analysis - U.S. 95 Styner-Lauder Avenue Intersection Questions to be answered: • Using the HCM, what would be the LOS at U.S. 95/Styner-Lauder Avenue during a University of Idaho football game if the intersection were signalized? • How would this LOS estimate change if a microscopic simulation model were used instead? • What would the critical movement analysis technique tell us about the intersection’s sufficiency under these circumstances?

3. Sub-problem 3a: Oversaturated Intersection Analysis • What is the difference between volume and demand, and why is it important to distinguish between these two terms? • Can the intersection operate at LOS F even when demand is less than capacity? • What is the appropriate value of the duration-of-analysis parameter when demand exceeds capacity? When should multiple time periods be considered in a capacity and level of service analysis?

4. Sub-problem 3a: Oversaturated Intersection Analysis • How will the intersection perform, under both signal control and stop sign control, for these demand conditions? • How should we proceed with this analysis?

5. Sub-problem 3a: Oversaturated Intersection Analysis Run US 95 1975 Lauder Styner 1025 Step 2. Results How will the intersection perform under signal control?

6. Sub-problem 3a: Oversaturated Intersection Analysis US 95 Styner Lauder Step 2. 1st period results: signal control

7. Sub-problem 3a: Oversaturated Intersection Analysis Step 2. 2nd period results: signal control

8. Sub-problem 3a: Oversaturated Intersection Analysis Step 2. 3rd period results: signal control

9. Sub-problem 3a: Oversaturated Intersection Analysis Step 2. 3rd period results: signal control

10. Sub-Problem 3b: Using a Microscopic Simulation Model Microscopic simulation models • HCM chapter 34 provides information on simulation models • Microscopic simulation has several distinct attributes: • Individual vehicle interactions • Detailed operation of traffic controllers • Oversaturated conditions can be directly modeled • Multiple period inputs • Probabilistic nature of traffic flow and driver behavior • More data are required • Needs to be calibrated to local conditions

11. Sub-Problem 3b: Using a Microscopic Simulation Model Screen capture from a typical CORSIM animated display What insights can we draw from a comparison of CORSIM and HCM results?

12. Problem 3c: Critical movement analysis • What is critical movement analysis? • What data are needed? • What outputs are produced? • Are the results any more or less valid than the results produced by the HCM or by microscopic simulation models? • Why is there virtually no difference between estimated delay on the eastbound and westbound approaches to the intersection? • What is the effect of grade and heavy vehicles? • How do changes in vehicle mix affect the intersections when the intersection operates near or at capacity? • What effects do heavy vehicles have on the intersection beyond changes to saturation flow rate?

13. Problem 3c: Critical movement analysis • What is critical movement analysis? • What data are needed to conduct critical movement analysis? Data necessary to conduct a critical movement analysis include: - Approach volume - Number of lanes - Lane configuration on each approach Critical movement analysis is a method to determine whether the projected volumes at a signalized intersection will be under, near, or over the intersection's capacity to accommodate them.

14. Problem 3c: Critical movement analysis • Are the results from critical movement analysis any more or less valid than the results produced by the HCM or by microscopic simulation models? • Why is there virtually no difference between estimated delay on the eastbound and westbound approaches to the intersection? • What is the effect of grade and heavy vehicles? • How do changes in vehicle mix affect the intersections when the intersection operates near or at capacity? • What effects do heavy vehicles have on the intersection beyond changes to saturation flow rate?

15. Problem 3c: Critical movement analysis • What is the primary result of critical movement analysis? • What are the limitations of critical movement analysis?

16. Problem 3: Analysis • The ability of a traffic signal to handle fluctuations is a function of the signal timing that is in the controller in the field. In time period 3 (4:30 - 4:45 pm) of our previous analysis, we changed the green ratio slightly to serve the traffic at the post-game traffic at the intersection. • Would this green ratio be possible under the existing pre-timed control?

17. Problem 3: Discussion Will the consideration of actuated traffic controller settings affect our analysis?

18. End of Problem 3