1) AMERICAN CONCRETE PIPE ASSOCIATION

2) DAUPHIN COUNTY, PA

3) HOOD RIVER-WHITE SALMON BRIDGE AUTHORITY

4) METROPOLITAN TRANSPORTATION COMMISSION

5) NATIONAL ASSOCIATION OF DEVELOPMENT ORGANIZATIONS

6) NATIONAL UTILITY CONTRACTORS ASSOCIATION (NUCA)

7) NORFOLK SOUTHERN

8) PROFESSIONAL ENGINEERS IN CALIFORNIA GOVERNMENT

9) THE ASSOCIATION OF UNION CONSTRUCTORS

10) THE DOERRER GROUP ON BEHALF OF UBER TECHNOLOGIES, INC.

11) TRI-COUNTY METROPOLITAN TRANSPORTATION DISTRICT OF OREGON (TRIMET)

12) WASHINGTON STATE DEPARTMENT OF TRANSPORTATION