Bridge Design Manual LRFD
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 23-50.20
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M 23-50.01 February 2007
November 2006
September 2006
August 2006
July 2005
April 2005
August 2002
14 fish passage projects were completed in 2020
improving access to 54.2 miles of upstream habitat.
11,959 incidents responded to
by WSDOT’s incident Response teams during second quarter of 2021, 15% more than same quarter in 2020.
41 Pre-existing Funds Projects Advertised
during the eighth quarter of the 2019-2021 biennium.