Pittsburgh Regional Transit is replacing four tunnel ventilation fans, controls, and other equipment that make up the emergency ventilation system of the Mt. Lebanon Transit Tunnel. 

The Mt. Lebanon Transit Tunnel spans from Mt. Lebanon Township to Dormont Borough. There are two ventilation fans and corresponding equipment on each side of the tunnel.  

PRT began running the emergency fans in November 2020 to help reduce moisture inside the tunnel in response to PennDOT inspectors discovering corrosion on metal infrastructure inside the tunnel, caused by moisture and condensation. 

The new fans will not only reduce moisture in the tunnel but will also be much quieter so that when they are in use, they should not be disruptive to residents and businesses.  

Currently the fans are scheduled to run Monday through Friday from 10am-2pm on alternating sides (Monday, Wednesday and Friday on the Mt. Lebanon side; Tuesday and Thursday on the Dormont side) to minimize disruption to residents.  



Construction began in January 2022. While completing electrical work, the contractor discovered that the metal conduit that carries electrical wires on both sides of the tunnel were damaged from moisture and must be replaced before the fans can be installed. The critical nature of this replacement significantly expands the scope of work.  

Therefore, this project will take several months longer to complete than we had originally anticipated. These delays are disappointing. However, residents and business will find that most of the additional work will not be disruptive.  

We are working with the contractor to develop a new schedule for the remaining work to be completed. Once available, the new schedule will be posted on this project webpage. 


If you have questions or concerns, please call PRT Customer Service at 412-442-2000 weekdays from 6am-7pm, and weekends from 8am-4:30pm. 

Contact Us About This Project

An error has occurred while getting captcha image