Intersection Geometric Design
In Intersection Geometric Design, you'll learn ...
- Variables for the type of intersection to be used at a location
- General design guidelines regarding horizontal and vertical alignment combinations
- Recommended sight triangle dimensions for different types of traffic control
- Left turn lane design guidelines
- Basic single lane and multilane roundabout design principles
Overview
This course summarizes and highlights the geometric design process for modern roadway intersections. The contents of this course are intended to serve as guidance and not as an absolute standard or rule.
When you complete this course, you should be familiar with the general guidelines for at-grade intersection design. The course objective is to give engineers and designers an in-depth look at the principles to be considered when selecting and designing intersections.
A Policy on Geometric Design of Highways and Streets (also known as the “Green Book”) published by the American Association of State Highway and Transportation Officials (AASHTO) is considered to be the primary guidance for U.S. roadway design. For this course, Chapter 9 - Intersections will be used exclusively for fundamental roadway geometric design principles.
Intersections are unique roadway elements where conflicting vehicle streams (and sometimes non-motorized users) share the same space. This area encompasses all modes of travel (pedestrian, bicycle, passenger vehicle, truck, and transit) as well as auxiliary lanes, medians, islands, sidewalks and pedestrian ramps. These may further heighten the accident potential and constrain the operational efficiency and network capacity of the urban street system. However, the main objective of intersection design is to facilitate the roadway user and enhance efficient vehicle movement.
Specific Knowledge or Skill Obtained
This course teaches the following specific knowledge and skills:
- Basic elements of intersection design
- Types of intersections
- Why the horizontal and vertical geometries are the most critical design elements of any roadway
- Design guidelines for intersection site distance
- Design of turning roadways based on various design vehicles
- Principles of channelization
- Purposes of islands and minimum curbed corner island area
- Auxiliary lane design guidance
- Length requirements for deceleration lanes
- Control radii for median openings
- Indirect left turns and U-turns
- Purpose, benefits and preferred sites for jughandles
- Basic principles for modern roundabouts
- Roundabout geometric elements and speed management
- Appropriate lane arrangements and path alignment for roundabouts
- Roundabout design considerations for pedestrians and bicycles
- Frontage road design considerations
- Elements of pedestrian facilities
- Types of curb ramps
- Factors to consider for accommodating bicycles
- Horizontal alignment guidelines for railroad-highway grade crossings
Certificate of Completion
You will be able to immediately print a certificate of completion after passing a multiple-choice quiz consisting of 25 questions. PDH credits are not awarded until the course is completed and quiz is passed.
This course is applicable to professional engineers in: | ||
Alabama (P.E.) | Alaska (P.E.) | Arkansas (P.E.) |
Delaware (P.E.) | District of Columbia (P.E.) | Florida (P.E. Area of Practice) |
Georgia (P.E.) | Idaho (P.E.) | Illinois (P.E.) |
Illinois (S.E.) | Indiana (P.E.) | Iowa (P.E.) |
Kansas (P.E.) | Kentucky (P.E.) | Louisiana (P.E.) |
Maine (P.E.) | Maryland (P.E.) | Michigan (P.E.) |
Minnesota (P.E.) | Mississippi (P.E.) | Missouri (P.E.) |
Montana (P.E.) | Nebraska (P.E.) | Nevada (P.E.) |
New Hampshire (P.E.) | New Jersey (P.E.) | New Mexico (P.E.) |
New York (P.E.) | North Carolina (P.E.) | North Dakota (P.E.) |
Ohio (P.E. Self-Paced) | Oklahoma (P.E.) | Oregon (P.E.) |
Pennsylvania (P.E.) | South Carolina (P.E.) | South Dakota (P.E.) |
Tennessee (P.E.) | Texas (P.E.) | Utah (P.E.) |
Vermont (P.E.) | Virginia (P.E.) | West Virginia (P.E.) |
Wisconsin (P.E.) | Wyoming (P.E.) |