In the National Tunnel Inspection Standards (NTIS) Final Rule, FHWA used the same definition of critical findings for highway tunnels as for highway bridges. The Tunnel Operations, Maintenance, Inspection, and Evaluation (TOMIE) Manual, incorporated into the regulation by reference, does not provide criteria for defining critical findings in functional systems. Tunnels have unique characteristics, which may include functional systems such as ventilation, lighting, drainage, fire/life safety/security, communications and signage for traffic management, and emergency evacuation. The intent of the NTIS and TOMIE Manual is that tunnel owners will define critical findings for each tunnel based on its unique characteristics.
The operation of functional systems is highly variable between different tunnels. Some may have different modes of function for emergencies such as fires in tunnels, while others do not. Some have automatic or remote controls that can alter operation modes in response to changing conditions, while others may have fixed modes of operation that can only be adjusted manually, or cannot be adjusted at all.
The objective of this synthesis is to document state DOT methods and criteria for defining critical findings for tunnel functional systems.
Information to be gathered includes (but is not limited to):
• Identification of state DOTs that have tunnels with functional systems as defined by NTIS section 650.505;
• State DOT procedures for defining critical findings in functional systems (e.g., statewide criteria, criteria for individual tunnels, inspector recommended);
• Basis for the critical findings criteria (e.g., original design, level of complexity, functional analysis, maintenance records, level of service, potential for imminent danger, AHJ involvement);
• Location of critical findings criteria documentation (e.g., tunnel specific documentation, generic state DOT inspection manuals); and
• Protocol for reporting critical findings to FHWA.
Information will be collected through a literature review, a survey of state DOTs, and follow-up interviews with selected agencies for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.
Information Sources (Partial):
• Tunnel Operations, Maintenance, Inspection, and Evaluation (TOMIE) Manual. (2015). FHWA--HIF-15-005. FHWA, U.S. Department of Transportation.
• LRFD Road Tunnel and Construction Guide Specifications. (2017).
AASHTO, Washington, D.C.
• National Tunnel Inspection Standards. (2018). ttps://www.fhwa.dot.gov/bridge/inspection/tunnel/ntis.cfm
Jo Allen Gause
First Panel: October 14, 2021, virtual
Teleconference with Consultant: November 8, 2021, 3:00 p.m, ET
Second Panel: June 29, 2022, Washington, DC
Rebecca L. Curtis, Michigan Department of Transportation
Stephen Harelson, Colorado Department of Transportation
Bijan Khaleghi, Washington Department of Transportation
Gregory M. Nataluk, Virginia Department of Transportation
Richard W. Runyen, Pennsylvania Department of Transportation
David Snoke, North Carolina Department of Transportation
Eric C. Wang, HNTB Corporation
Stephen Bartha, Federal Highway Administration
Stephen F. Maher, Transportation Research Board