Real property or real property interest means any interest in land and any improvements thereto, including fee and less-than-fee interests such as: temporary and permanent easements, air or access rights, access control, options, and other contractual rights to acquire an interest in land, rights to control use or development, leases, and licenses, and any other similar action to acquire or preserve ROW for a transportation facility. As used in this part, the terms real property and real property interest are synonymous unless otherwise specified.
23 CFR § 710.105
Terms defined in 23 U.S.C. 101(a) and 49 CFR part 24 have the same meaning where used in this part, except as modified in this section.