49 C.F.R. § 213.59 Elevation of curved track; runoff.
Title 49 - Transportation
(a) If a curve is elevated, the full elevation shall be provided throughout the curve, unless physical conditions do not permit. If elevation runoff occurs in a curve, the actual minimum elevation shall be used in computing the maximum allowable operating speed for that curve under §213.57(b). (b) Elevation runoff shall be at a uniform rate, within the limits of track surface deviation prescribed in §213.63, and it shall extend at least the full length of the spirals. If physical conditions do not permit a spiral long enough to accommodate the minimum length of runoff, part of the runoff may be on tangent track.
Title 49: Transportation
PART 213—TRACK SAFETY STANDARDS
Subpart C—Track Geometry
§ 213.59 Elevation of curved track; runoff.
