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Getting Started
Problem 1
Problem 2
Problem 3
Problem 4
Problem 5
Problem 6
Problem Index

Getting Started - Page 3 of 5

ID# C1GS003

Getting Started

Performance Measures
The Highway Capacity Manual provides several performance measures for intersections, both signalized and unsignalized. For both of these types of intersections, the primary measure of effectiveness is control delay. Control delay is directly related to level of service, a range of levels that categorize performance from the point of view of the driver, or the user of the highway system. Level of service (along with delay) will be used here to help us determine if the intersection of U.S. 95/Styner Avenue/Lauder Avenue should be changed from stop sign control to signal control.

We will also need to consider other performance measures besides just level of service in order to fully judge the overall performance characteristics of the intersection. Depending on the type of control at the intersection, these may include the volume/capacity ratio of the critical movements at the intersection, the traffic signal cycle length, and/or queue length considerations.

We must complete several computations in order to gather the required information on the performance of the U.S. 95/Styner-Lauder Avenue under both stop sign and signal control. For convenience, we've divided the analyses into six parts or problems. We will consider each problem separately. We will also see that each problem consists of several separate computations, using the Highway Capacity Manual or other tools, such as TRANSYT 7F or CORSIM.


In Problem 1, we will study the intersection under both stop sign and signal control under both present and future traffic conditions, for the typical weekday found in Moscow, Idaho.


In Problem 2, we will consider these same conditions, but within the context of the U.S. 95 arterial as a whole. Here, we will particularly focus on the effect that the adjacent intersections have on the U.S. 95/Styner-Lauder Avenue intersection, and how a new signal at this intersection must operate in conjunction with the adjacent signalized intersections.


In Problem 3, we will consider other time periods, including traffic volumes during special events at the University of Idaho and during different times of the year, when the mix of vehicles in the traffic stream changes.


In Problem 4, we will consider how we can forecast the performance of the U.S. 95/Styner-Lauder Avenue intersection when an actuated traffic controller is used.


In Problem 5, we will consider the operation of the highway outside the city limits, where it is operating as a two-lane highway.


In Problem 6, we will consider the less detailed planning analysis and what information it can tell us about future operations of the intersection and the corridor.

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