Print this page Drainage of Highway Pavements
Vincent D. Reynolds, MBA, P.E.
Course Outline
This course will discuss the hydrology and hydraulics of highway pavement drainage. The methods for determining flow including how to determine the time of concentration will be discussed. Included in the hydraulic discussion will be the design aids for determining gutter spread and grate selection.
This 8 hour course will provide the reader with the knowledge to design an efficient pavement drainage system.
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:
- When check storms are used in designing gutter spread limits;
- The most commonly used method for estimating runoff for highway pavement drainage;
- How to determine runoff using the rational method;
- Assumptions made when using the rational method;
- When grates perform as weirs and when they perform as orifices;
- How to determine the time of concentration;
- How depressed curb-inlets perform;
- How roadway cross slope affects gutter spread;
- How to determine the time of flow in a gutter;
- How to determine the flow in a rectangular channel;
- How to determine the flow rate in a section of gutter;
- How longitudinal slope affects gutter spread;
- How to determine gutter spread;
- They major classes of inlets used for drainage;
- How to determine the efficiency of an inlet;
- How to determine curb inlet bypass flow;
- How to determine the flow through a weir;
- When curb-opening inlets operate as weirs;
- The most efficient depth of inlets;
- How to determine the average debris handling efficiency of various grates;
- The most efficient drainage structures for low points;
- When combination inlets are most effective;
- How to design slotted inlets;
- How to define shallow concentrated flow;
- The minimum slope to provide adequate drainage in a sag vertical curve;
- The suggested rates of change for various pavement surfaces;
- Measures to decrease gutter spread;
- How medians are drained;
- The design frequency that should be used in determining gutter spreads;
- How water can be drained before it reaches the roadway;
- How to determine the flow through an orifice; and
- How roadway geometry affects the gutter spread.
Intended Audience and Benefit
This is intended for highway engineers, drainage engineers, planners, traffic engineers, designers, and project managers, any persons working in civil engineering field or anyone with an interest in drainage of highway pavements.
Course Introduction
Effective highway drainage is essential to the proper function traffic along the highway. Water on the pavement can cause several problems such as hydroplaning, and visibility from splash and spray. Water on the roadway could also inhibit the proper flow of traffic increasing congestion.
Course Content
This course will discuss the hydrology and hydraulics of highway pavement drainage. The methods for determining flow including how to determine the time of concentration will be discussed. Included in the hydraulic discussion will be the design aids for determining gutter spread and grate selection. The course material is based on the document “Drainage of Highway Pavements,” as published on the website of the Federal Highway Administration.
Please click on the above underlined hypertext to view, download or print the document for your study. Because of the large file size, we recommend that you first save the file to your computer by right clicking the mouse and choosing "Save Target As ...", and then open the file in Adobe Acrobat Reader. If you still experience any difficulty in downloading or opening this file, you may need to close some applications or reboot your computer to free up some memory.
Course Summary
The information presented will provide a detailed overview of how highway pavements drain and how to design a drainage system to facilitate the safe passage of traffic during the design storm.
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 efficient highway drainage systems.
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.
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.
