CEMP-E
TI 850-02
AFMAN 32-1125(I)
1 MARCH 2000
(6) If the track approaching the crossing is anchored, it is recommended that each tie in the crossing
be box anchored and that the normal anchoring pattern be maintained throughout the remainder of the
crossing area (20 ft off each end).
(7) Once a conventional crossing surface is in place, the track will be covered, making maintenance
difficult and costly, thus the track geometry (gage, surface and alignment) should be nearly perfect before
placing the crossing surface. The ballast in and around all the ties should be well compacted to prevent
settlement and movement of the crossing.
(8) Crossing flangeways should have a minimum width of 2.5 in. with a maximum width of 3 in. and
be at least 2 in. deep.
g. Road Approaches.
(1) To reduce the amount of runoff water directed toward the crossing, road approaches are best
sloped away from the crossing.
(2) To achieve smooth riding characteristics, road approach slopes are best kept within the limits
shown in figure 7-3, however, the difference in elevation between the railroad and the adjacent roadway
may require steeper approaches. Ascending road approaches must not be so steep that long flatbed
truck trailers, for example, with low ground clearance might contact the crossing. On descending road
approaches, gradients must not excessively lengthen stopping distances for vehicles approaching the
crossing including an allowance for wet or icy pavement.
Figure 7-16. Recommended Crossing Road Approach Profile
h. Crossing Protection: Signs and Signals.
(1) Specifications and Minimum Requirements. Specifications for the basic design and appearance
of crossing warning signs, pavement markings, and warning signals is given in Part 8 of the Manual of
Uniform Traffic Control Devices (USDOT-FHWA). All road crossings will have, at minimum, the standard
warning signs shown in the MUTCD. The need for additional signs, flashing lights, or gates, depends on
crossing visibility, traffic character and volume, crossing geometry, and accident and incident history, as
described below. Further guidance on providing crossing warnings and protection can be found in the
FHWA Railroad-Highway Grade Crossing Handbook.
7-19
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