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 23-50.21
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
We are hiring!
We have a range of positions open across the state - view all current job openings.
Improved access to 98.2 miles of upstream fish habitat
through 15 fish passage projects in 2021.
28% increase in the value of exports and imports
from $90.2 billion in 2020 to $115.5 billion in 2021.