Iowa Admin. Code r. 761-813.4
"Close clearance " means a permanent or temporary situation where an obstruction near a railroad track physically impedes a person who is lawfully riding the side of a train from clearing the obstruction. Rule 761-813.5 (327F) provides further detail on the dimensions that identify a close-clearance situation.
"Obstruction" means a building, machinery (other than equipment designed for operation on a railroad track when actually located on a railroad track), tree, brush or other object.
"Owner " means the railroad company, industry, agricultural cooperative, other entity, or individual that holds a fee simple title, easement, leasehold, contract to purchase, license, or other legal or equitable interest or right in the railroad track, and is in primary possession and control of the railroad track.
"Tangent track" means a track segment without any curves.
Iowa Admin. Code r. 761-813.4