Bridge Design Manual LRFD

Publication Version
M 23-50.21
Manual Manager
Mike Rosa,
Bridge and Structures Office, Engineering and Regional Operations Division


    This manual has been prepared to provide Washington State Department of Transportation (WSDOT) bridge design engineers with a guide to the design criteria, analysis methods, and detailing procedures for the preparation of highway bridge and structure construction plans, specifications, and estimates.

    Bridge Design Manual Memorandums 

    Bridge design memorandums are issued as interim updates to the Bridge Design Manual. 

    Active design memorandums supersede the contents of the Bridge Design Manual and are currently in force. View Active Bridge Design Manual memorandums

    Inactive memorandums provide historical context and background on design policies incorporated into the Bridge Design Manual. View Inactive Bridge Design Manual memorandums.

    Individual Chapters

    Contents (PDF 278KB)
    Foreword (PDF 96KB)

    Chapter 1 General Information (PDF 1.0MB)
    Chapter 2 Preliminary Design (PDF 3.6MB)
    Chapter 3 Loads (PDF 906KB)
    Chapter 4 Seismic Design and Retrofit (PDF 4.7MB)
    Chapter 5 Concrete Structures (PDF 18.2MB)
    Chapter 6 Structural Steel (PDF 2.2MB)
    Chapter 7 Substructure Design (PDF 2.4MB)
    Chapter 8 Walls and Buried Structures (PDF 3.0MB)
    Chapter 9 Bearings and Expansion Joints (PDF 1.5MB)
    Chapter 10 Sign, Barriers, Approach Slabs, and Utilities (PDF 8.6MB)
    Chapter 11 Detailing Practice (PDF 1.4MB)
    Chapter 12 Quantities, Costs, and Specifications (PDF 2.5MB)
    Chapter 13 Bridge Load Rating (PDF 1.9MB)
    Chapter 14 Accelerated and Innovative Bridge Construction (PDF 2.5MB)
    Chapter 15 Structural Design Requirements for Design-Build Contracts (PDF 1.5MB)

    Revision History

    M 23-50.21

    M 23-50.20

     M 23-50.19 

    M 23-50.18 

    M 23-50.17  

    M 23-50.16 

    M 23-50.15 

    M 23-50.14

    M 23-50.13 

    M 23-50.12

    M 23-50.11

    M 23-50.10

    M 23-50.09 

    M 23-50.08

    M 23-50.07 

    M 23-50.06 

    M 23-50.05 

    M 23-50.04 

    M 23-50.03 

    M 23-50.02 

    M 23-50.01 February 2007

    November 2006

    September 2006

    August 2006

    July 2005

    April 2005

    August 2002

    Traction tires are a special type of tire

    manufactured with at least 1/8 of an inch tread. Traction tires are usually marked with a mountain/snowflake symbol, the letters M+S or “All Season.”

    Carry chains, practice before leaving

    Requiring chains keeps traffic moving during storms rather than closing a pass or roadway.

    Prep your car. Fill up your gas tank,

    pack jumper cables, ice scraper, warm clothing, snacks and water.