Case Study 1 Styner/Lauder Intersection Moscow, Idaho

Problem: Should the intersection of U.S. 95 and Styner/Lauder be converted from two way stop control to signal control? Learning skills: Apply HCM analysis procedures for interrupted flow facilities. Know common input requirements and default values. Select an appropriate analysis procedure Understand HCM analysis limitations Know how to reasonably interpret the results ? US 95 SH 8 Lauder Styner Sweet Overview

Moscow’s population is about 21,000 U.S. 95 is the primary north-south state highway in Idaho ADT on U.S. 95 is between 15,000 and 23,000 vpd Average annual traffic growth is about two percent per year Introduction

SH 8 US 95 Sweet Lauder Styner Introduction SH 8 Sweet Lauder

What issues do you think should be considered by the state's traffic engineer in resolving this problem? Introduction What issues do you think should be considered by the state's traffic engineer in resolving this problem? City residents have asserted that increasing traffic volumes at the intersections of Styner Avenue, Lauder Avenue, and U.S. 95 are increasing delays for and reducing the safety of motorists traveling through the intersection. The city has requested that the Idaho Transportation Department signalize the intersection.

Issues to consider Scope of the analysis? Stakeholders? Goals? Performance measures? Tools? Data? Technical Issues? Getting Started

Questions to be Answered: What is the level of service at the existing TWSC intersection at U.S. 95/Styner-Lauder? What would the level of service be if the intersection were signal controlled? What would the level of service be at the intersection under future projected traffic conditions? US 95 Lauder Styner Problem 1 U.S. 95/Styner- Lauder Avenue

Sub-problem 1a. Analysis of the existing TWSC intersection Sub-problem 1b. Analysis of the proposed signalized intersection Sub-problem 1c. Analysis of future conditions US 95 Lauder Styner Problem 1 U.S. 95/Styner- Lauder Avenue Analyses to be Undertaken:

Step 1. Setup: analysis of existing TWSC Which tool or tools from the HCM should be used for the analysis of a TWSC intersection? What data are required for the analysis? What default values should be used? What time periods should be analyzed? What measure should be used to determine the performance of the intersection? What other factors should be considered? US 95 Lauder Styner Sub-Problem 1a Analysis of existing TWSC intersection

US 95 Lauder Styner Sub-Problem 1a Analysis of existing TWSC intersection

Sub-Problem 1a Analysis of existing TWSC intersection Step 2. Results

Sub-Problem 1a Analysis of existing TWSC intersection Step 2. Results (cont.)

Sub-Problem 1a Analysis of existing TWSC intersection Intersection delay and LOS? Step 2. Results (cont.)

Step 1. Setup: analysis of signal control Which tool or tools should be used for this analysis? What data are required for the analysis? What default values should be used? What time periods should be analyzed? How do we construct a signal timing for a proposed traffic signal using the HCM? US 95 Lauder Styner Sub-Problem 1b Analysis of proposed signalized intersection

Sub-Problem 1b Analysis of proposed signalized intersection Step 2. Results

Step 1. Setup: analysis of future conditions What is the appropriate future year for this analysis? Which default values should be used for this future analysis? What other factors should be considered? US 95 Lauder Styner Sub-Problem 1c Analysis of future conditions

Sub-Problem 1c Analysis of future conditions Today Future Step 2. Results for TWSC control

Sub-Problem 1c Analysis of future conditions Step 2. Results for signal control

Sub-Problem 1c Analysis of future conditions What if our volume assumptions are uncertain?

Sub-Problem 1c Analysis of future conditions Graphical presentation of results

Sub-Problem 1c Analysis of future conditions Graphical presentation of results

Problem 1 Analysis

Problem 1 Discussion

End of Problem 1