Signalized Intersections Part I - Fundamentals

Vincent D. Reynolds, MBA, P.E.

Course Outline

The basic function of signalized intersections is to sequence right-of-way between intersecting streams of users. Research has shown that, under the right circumstances, the installation of traffic signals will reduce the number and severity of crashes.

This 7 hour course is the first part of a three part series and will introduce to the reader to the fundamentals of signal design including user needs, geometric design, and traffic design and illumination.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of course materials.

Learning Objective

At the conclusion of this course, the student would have learned the following:

• Principles of channelization;
• Number of intersection approaches;
• Corner radius and curb ramp design;
• Vehicle and pedestrian detection;
• Traffic signal pole layout;
• Basic signal timing parameters;
• Signing and pavement markings;
• Traffic signal phasing;
• Traffic signal control types;
• How traffic signals reduce the number and severity of crashes;
• The basic function of signalized intersections;
• The effects of slow reaction times;
• Driving tasks that are problematic for older road users;
• The type of crash that occur most frequently at signalized intersections;
• Drivers that are most likely to violate red lights;
• The walking speed of pedestrians used in design;
• How sight distance can be impacted;
• The primary goal of intersection design;
• The effects of using small or large turning radii;
• The characteristics of skewed intersections;
• The psychological steps that occur in order to see an object;
• The effects of speed differentials between vehicles;
• How to determine the design stopping sight distance;
• How to determine the decision sight distance;
• The primary types of signal configurations;
• The types of traffic controllers;
• How to determine pedestrian clearance time; and
• How to determine the change period (CP).
  

Intended Audience and Benefit

This is intended for planners, traffic engineers, highway engineers, designers, operation analysts, project managers, or any persons working in civil engineering field or anyone with an interest in signalized intersections.

Course Introduction

Intersections occur along roadways in order to connect intersecting streams of traffic. Several conflicts can occur at intersections which involve pedestrians, vehicles, and bicycles. These conflicts can be classified as merging, diverging and crossing. The basic function of signalized intersections is to sequence right-of-way between intersecting streams of users. Research has shown that, under the right circumstances, the installation of traffic signals will reduce the number and severity of crashes.

Course Content

This course will introduce to the reader to the fundamentals of signal design including user needs, geometric design, and traffic design and illumination. The introduction and chapters 2-4 are the sections that are required to be read in order to complete the quiz for this Part of the series; the remaining chapters are covered in Parts II and II of this course:

Signalized Intersections Part I - Fundamentals

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Course Summary

The information presented in this course provided a detailed overview of the design and operation of signalized intersections.
 
Using good engineering judgment is always paramount in any situation. Utilizing good judgment and the knowledge gained in this course will aid the reader with the knowledge to successfully design safe and efficient signalized intersections.

Related Links

For additional technical information related to this subject, please visit the following websites:

http://www.fhwa.dot.gov/
www.aashto.com
www.ite.com

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

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DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.

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