In the National Tunnel Inspection Standards (NTIS) Final Rule, FHWA used the same definition of critical findings 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, including critical functional systems for ventilation, lighting, drainage, fire/life safety/security, 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 condi-tions, 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 and those that do not;
• Current and proposed methodologies and criteria for defining critical findings in functional systems; and
• Types of tunnel functional systems for critical levels of function.
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). https://www.fhwa.dot.gov/bridge/inspection/tunnel/ntis.cfm
Jo Allen Gause
First Panel: October 14, 2021, virtual
Teleconference with Consultant: TBD
Second Panel: TBD