This bill amends title 49, United States Code, to clarify and expand the types of real property interests that can be acquired using federal transit assistance. It replaces references to "corridor preservation" and "right-of-way" with the broader term "real property interests" in existing law, requiring the Federal Transit Administration to update its guidance accordingly within six months. A significant provision allows recipients of federal financial assistance for passenger rail projects to acquire, lease, or otherwise secure real property interests before or during the completion of environmental reviews. This aims to streamline the project development process by enabling earlier land acquisition. However, to maintain environmental safeguards, the bill explicitly prohibits any physical development or improvement of such acquired property until all required environmental reviews for the project have been successfully completed.