transmission lines running through countryside
Trans-Allegheny expands mid-Atlantic transmission lines

An early method of high-voltage direct current transmission was first installed in Italy in 1889, transmitting 14 kilovolts over a distance of 120 kilometers. By the early 20th century, electricity transmitted by lines and grids ushered in a modern way of life for most industrialized nations.

The proposed Trans-Allegheny Interstate Line (TrAIL) called for the construction of a new 240-mile transmission line from southwestern Pennsylvania to northern Virginia. It would include three 138-kilovolt lines south of Pittsburgh and nearly 180 miles of 500-kilovolt lines linking substations in Pennsylvania, West Virginia and Virginia.

Louis Berger was retained by TrAILCo (an Allegheny Energy subsidiary) to conduct a siting study and environmental evaluations. The firm undertook route planning, facilitated public meetings and prepared line route evaluation reports. Louis Berger staff testified before state utility regulatory authorities in several states and provided analytical support for legal brief preparations. Public comments and agency input on line siting alternatives were incorporated into the analysis of alternative routes.

The TrAIL project was approved in 2008 by West Virginia and Virginia and by key portions of Pennsylvania. The project benefits the mid-Atlantic region by:

  • Improving system reliability.
  • Meeting the growing demand for electricity.
  • Increasing electricity transfer capability.
  • Providing cost-effective generation.