Design Memorandum

TO:                  All Design Section Staff

FROM:            Bijan Khaleghi
DATE:             April 14, 2010
SUBJECT:       Bridge Load Rating Policy

Load ratings are required for all new, widened, or rehabilitated bridges where rehabilitation alters the structure’s load carrying capacity. Load ratings shall be done immediately after the design is completed, and rating calculations shall be filed separately and submitted to the WSDOT’s Load Rating Engineer:

    Mohamad Al-Salman, PE

    Washington State Department of Transportation
    Bridge Preservation Office (360) 570-2567

This new load rating policy is effective May 1, 2010, and applicable to all WSDOT new and ongoing designs.


FHWA requires all bridges to be load rated within 90 days of opening to traffic. Many DOTs have been load rating bridges immediately after completing the design. Ratings serve as a good check on the design. To comply with FHWA’s regulation and align ourselves with the rating practice in other states, WSDOT is implementing this policy. The PGSuper program is being updated to perform load ratings of precast prestressed girder bridges. Other software and spreadsheets, as approved by the Load rating Engineer, may also be used for other bridge types. The Bridge Preservation Office will have new load rating software ready in the near future.

If you have any questions regarding this issue, please contact Mohamad Al-Salman at 570-2567, Rick Brice at 705-7174 or Bijan Khaleghi at 705-7181.

cc:   Mohammad Sheikhizadeh, Bridge Construction - 47354

       F. Posner, Bridge and Structures – 47340

Note:   Click here for a PDF of this design memo.