The 2015 Bridge Design Manual was developed to provide guidance to design engineers, technicians, and inspection personnel engaged in bridge design, plan preparation, construction, and inspection activities for the New Hampshire Department of Transportation. It encourages uniform application of design methodology and criteria, as well as standard details in plan preparation for bridges and other related structures.

This Manual is intended to supplement and provide interpretation of the AASHTO LRFD Bridge Design Specifications and is an aid for the layout, design, and preparation of plans and details for highway structures. It is not intended to be a textbook on structural engineering, but instead is a guide to general practices followed by NHDOT Bridge Design personnel.

This Manual does not address all conceivable problems that may arise during the project development/design process, but is intended to be a sufficiently comprehensive bridge engineering guide when applied with sound engineering judgment.  A thorough knowledge of the contents of this Manual is essential for efficient engineering of NHDOT highway structures.

The Bridge Design Manual should be used in conjunction with the Bridge Design Drawings (Bridge Detail Sheets, Bridge Details, and Sample Plans). It does not replace, modify, or supersede any provisions of the New Hampshire Standard Specifications, plans, or contracts.

Updating the Bridge Design Manual is a continual process, with revisions being made periodically. Suggestions for improvements and updating of this Manual are always welcome. Design changes will be issued through Design Memorandums, which will remain in effect until superseded by an update to the Bridge Design Manual. Changes to this Manual must be approved by the Administrator of the NHDOT Bridge Design Bureau.