Northwestern University has added ~19,000 bibliographic records for environmental impact statements and drafts, to the TRIS database. “The Transportation Research Information Services (TRIS) Database is the world’s largest and most comprehensive bibliographic resource on transportation information. TRIS is produced and maintained by the Transportation Research Board at the National Academy of Sciences.” This is a free web-based database.
The Library has recently subscribed to the Environmental Impact Statements database from CSA: Environmental Impact Statements: Full-Text & Digests
The collections do not appear to overlap, so there must be at least some unique EISs in each. Both these databases are listed in the “Articles and Databases” groupings.