FHWA Has Made Progress Implementing a Tunnel Safety Program, but Work Remains To Complete a Reliable Inventory, Fully Assess Compliance, and Effectively Monitor Critical Risks

What We Looked AtTunnels are important parts of the Nation’s highway infrastructure. According to the Federal Highway Administration (FHWA)—the Agency responsible for overseeing tunnels—an average of 15 million vehicles a day travel through more than 500 tunnels on public roads across the country. The majority of these tunnels have exceeded their designed service lives, and timely and reliable inspections help detect safety problems and prevent failures. The Moving Ahead for Progress in the 21st Century Act of 2012 (MAP-21) required FHWA to implement a tunnel safety program. Given the importance of FHWA’s role in tunnel safety, we conducted this audit to assess the Agency’s progress in implementing its tunnel safety program. Specifically, we focused on FHWA’s (1) maintenance of a national tunnel inventory, (2) compliance review process, and (3) monitoring of critical risks to tunnel safety.What We FoundFHWA has made progress implementing a comprehensive tunnel safety program as required by MAP-21 by establishing a national tunnel inventory, inspection standards, training for tunnel inspectors, and annual compliance reviews. However, we found that FHWA’s national tunnel inventory is incomplete because the Agency has not provided clear guidance to its Divisions and the State DOTs on how to classify some types of structures as tunnels and verify that they have inventoried all tunnels. Inaccurate and unreliable data also persist in the inventory due to inadequate data processing procedures that do not flag errors or require corrections. In addition, some internal controls for FHWA’s tunnel safety compliance review process are ineffective, resulting in compliance determinations that do not reflect the severity of deficiencies or adhere to the Agency’s review criteria. Lastly, FHWA has created an internal database to monitor critical tunnel safety risks, but the database lacks a clear scope and detailed guidance to help ensure that Division staff input complete and accurate data.Our RecommendationsWe made 12 recommendations to help FHWA improve the implementation of its tunnel safety program. FHWA concurred with seven recommendations and partially concurred with the other five. In response, we requested that FHWA clarify and reconsider its actions.