Allegheny Tunnel Transportation Improvement Project

Frequently Asked Questions

1. Where is the Allegheny Tunnel?

The Allegheny Tunnel is located approximately 13 miles east of Exit 110 (Somerset, PA) and 23 miles west of Exit 146 (Bedford, PA) on the Pennsylvania Turnpike. It spans the townships of Allegheny and Stonycreek in Somerset County. The approximate center of the project area is located at Latitude 39° 57’ 47.3” North and Longitude - 78° 51’ 02.8” West. Please refer to the project location map found on this website.

2. What is the purpose of the project?

The Allegheny Tunnel Transportation Improvement Project was initiated by the Pennsylvania Turnpike Commission (PTC) in 1996 as a result of increasing concerns regarding:

  • Traffic congestion

  • Frequency and severity of accidents in the vicinity of the tunnel

  • Physical and structural conditions of the tunnel

  • Rerouting of hazardous materials, which are prohibited in the tunnels, onto alternate routes.

3. Why is the project needed?

The project needs were established in 1997 and re-assessed in 2010. A project need equates to an issue or problem identified for a particular project. Five needs are established for this project:

  • Transportation Demand: The current and future transportation demands on the tunnel and its approaches result in unacceptable Levels of Service (LOS) and traffic congestion.

  • Existing Geometric Constraints: Some geometric features of the tunnel and its approaches do not meet current highway design standards with respect to lane width, termination of truck climbing lane, horizontal curvature, and sight distance.

  • Accident Rates: The accident rate for the tunnel and its approaches is higher than the entire turnpike system and PennDOT statewide rates.

  • Tunnel Conditions: Both the eastbound and westbound tunnels are in need of major rehabilitation.

  • System Linkage and Continuity (continuous travel without required exiting): System linkage and continuity on the turnpike is currently disrupted due to the fact that certain hazardous materials are not permitted through the Allegheny Tunnel (diversion of hazmat haulers to local roads).

4. What phase is the study in?

The Allegheny Tunnel Transportation Improvement Project is currently in the study (alternatives analysis) phase.

5. What type of alternatives are being evaluated?

Three project corridors (brown, yellow and gray) are being evaluated. Each corridor consists of one open-cut alternative and one tunnel alternative.

6. What is the goal of the study?

The goal of the study is to identify a preferred alternative to move forward to preliminary design.

7. What will the study evaluate?

  • Project purpose and need
  • Environmental constraints
    • Natural
    • Cultural
    • Social
    • Hazardous materials
    • Noise

  • Traffic
  • Accident data
  • Roadway data
  • Utility locations
  • Weather
  • Emergency response routes
  • Public Involvement
  • Agency Involvement
  • Permit needs
  • Mitigation measures

8. How can I keep informed of the study’s progress?

The project website will be updated regularly. In addition, you may click here to sign up to be included on a list to receive project updates.