Austin, TX – From the early days of the Republic through the Civil War and beyond, Texans have a rich and wild history. The Texas Department of Transportation (TxDOT) works hard to identify, document, and preserve aspects of that history affected by its projects. That job has gotten considerably easier with TxDOT’s implementation of the Texas Historic Overlay, an innovative statewide GIS-driven database that helps identify historic-period cultural resources that may be affected by highway construction and operation.

Developed by PBS&J, this database contains geographically corrected overlays of historic map images depicting cultural resource features and localities. In total, this database incorporates more than 3,000 maps dating back up to 300 years. The Texas Historical Overlay information is integrated into TxDOT’s existing statewide GIS and distributed to TxDOT archeologists, historians, and other professionals for use in planning highway construction and improvement projects.

Jim Abbott, Project Manager for TxDOT’s Environmental Division, says, “The ability to access and compare historic maps at the desktop provides us with a powerful tool for cultural resource planning. With the Texas Historic Overlay, we can quickly and consistently locate and avoid possible historic archeological sites that otherwise might be missed in planning for highway projects.”

The greatest challenge of this multi-year effort, beyond the gathering of thousands of maps, was georeferencing the multiple coordinate systems, many that predate the North American Datum of 1927, to a modern coordinate system. PBS&J developed customized datum transformations to translate the historic maps into a modern coordinate system.

Donna Huey, vice president and national business sector manager for PBS&J’s Information Solutions Division said, “PBS&J is proud to work with TxDOT on this innovative program. The Texas Historic Overlay project redefines cultural resource management in many ways, while driving efficiency in highway management and construction throughout the state of Texas.” 

The Texas Historic Overlay data is now available to TxDOT and approved consultants to manage the state’s cultural resources and develop historic trends in land use, development, and vegetation. Although some maps are restricted as a result of agreements between TxDOT and the individual libraries and repositories that own the paper copies, the remainder of the maps are available to the public through the Texas Natural Resource Information System website at www.tnris.org.

TxDOT is responsible for planning, designing, building, operating and maintaining almost 80,000 miles of state-owned and maintained roadways in Texas, the second most populated state in the United States.

About PBS&J
PBS&J (www.pbsj.com) is an employee-owned firm that provides infrastructure planning, engineering, construction management, architecture, and program management services to public and private clients. The firm is ranked by Engineering News-Record as 22nd among the nation’s top consulting firms. PBS&J has 3,900 employees and more than 75 offices located throughout the United States and abroad.