Publication Number: FHWA-HRT-06-020
Date: November 2005

Road Tunnel Design Guidelines Available from FHWA

Over the past 10 years, major road tunnel projects have been built across the United States, from Massachusetts to Arkansas to Alaska. These tunnels were built using generally accepted procedures greatly influenced by bridge standards and specifications developed by the American Association of State Highway and Transportation Officials and other organizations. However, uniform national standards or guidelines have not existed. "Many designers have expressed a need for some type of design standards in these areas. There was a gap that needed to be filled," says Jesus Rohena, Senior Tunnel Engineer for the Federal Highway Administration (FHWA). "Also, because there has been little uniformity of approach to tunnel designs in the past, there are now widely varying designs and in some cases projects are over designed," notes Rohena. To help fill the void, FHWA has developed the FHWA Road Tunnel Design Guidelines (Publication No. FHWA-IF-05-023).

The guidelines provide general technical design criteria for such topics as:

• Planning.
• Studies and investigations.
• Design, including such components as soft ground tunneling, rock tunneling, mixed-face tunneling, shafts, and immersed tunnels.
• Cut-and-cover techniques.
• Seismic design.
• Security.
• Fire precautions.
• Lighting.
• Ventilation.
• Construction.
• Tunnel boring machines.

The next phase of FHWA's initiative is to expand the guidelines and develop a Road Tunnel Design Manual. "The manual will be more detailed, covering procedures and all the steps that need to be followed to design a tunnel," says Rohena. The manual will incorporate the latest accepted national and international technologies and methods for design and construction of long-lasting tunnels. It is expected to be completed in 2007.

To obtain a copy of the FHWA Road Tunnel Design Guidelines, contact the National Technical Information Service (NTIS) at 800-553-6847 or 703-605-6000 (fax: 703-605-6900; email: info@ntis.gov; Web: www.ntis.gov). The NTIS document number for the guidelines is PB2006100660. For more information about the guidelines, contact Jesus Rohena at FHWA, 202-366-4593 (fax: 202-366-3077; email: jesus.rohena@fhwa.dot.gov).

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