(4) A height within an en route obstacle clearance area, including turn and termination areas, of a
Federal airway or approved off-airway route that would increase the minimum obstacle clearance altitude.
(5) The surface of a takeoff and landing area of an airfield or any imaginary surface established
under 77.25, 77.28, or 77.29 (of FAA Part 77). However, no part of the takeoff or landing area itself
will be considered an obstruction.
(b) Except for traverse ways on or near an airport with an operative ground traffic control service,
furnished by an air traffic control tower or by the airport management and coordinated with the air traffic
control service, the standards of paragraph (a) of this section apply to traverse ways used or to be used for
the passage of mobile objects only after the heights of these traverse ways are increased by:
(1) Seventeen feet [5.18 m] for an Interstate Highway that is part of the National System of
Military and Interstate Highways where over crossings are designed for a minimum of 17 feet [5.18 m]
(2) Fifteen feet [4.57 m] for any other public roadway.
(3) Ten feet [3.05 m] or the height of the highest mobile object that would normally traverse the
road, whichever is greater, for a private road.
(4) Twenty-three feet [7.01 m] for a railroad.
(5) For a waterway or any other traverse way not previously mentioned, an amount equal to the
height of the highest mobile object that would normally traverse it.