Site preparation work is underway for a new warehouse complex to be constructed on 25.5 acres of land at 7175 Tilghman St., west of the street’s intersection with Mill Road, Upper Macungie Township.

To ease congestion along already busy Tilghman Street, plans call for expanding the Mill and Windsor roads intersection at Tilghman Street, and widening Tilghman Street east of the site, which developers say will include 336,000 square feet for warehouse space.

The estimated $1.1 million cost for the work will nearly all be covered through an agreement in place between the Upper Macungie Township and Amgen USA, the current landowner, which has been granted a deferral on real estate taxes in exchange for funding future road improvements.