June 99
J.
Profiles of roads, including:
1.
All changes in grade connected by parabolic
vertical curves of such lengths as to provide safe
sight distance. Minimize vertical curves between
relatively flat grades to ensure proper drainage.
Avoid sharp horizontal curves at the apex of peak
vertical curves.
2.
Vertical curve data consisting of:
a.
Total length of curve (L);
b.
Stationing at the point of vertical curve (PVC),
point of vertical tangents intersection (PVI),
point of vertical tangent (PVT), low point (LP),
and high point (HP) of the curve;
c.
Curve elevations for all stations in b above;
d.
Tangent gradients; and
e.
Vertical curve number for identification.
9.6
Grading guidelines:.
Maximum
Minimum
Condition
Slope
Slope
Preferred
Lawns (Interment Areas)
15%
6.7:1
2%
50:1
2- 10%
Mowed slopes
25%
4:1a
2%
50:1
Road crown
3%
33.3:1
2%
50:1
2%
*Roads, longitudinal
10%
10:1
1%
100:1
1-10%c
Walks, longitudinal
5%
10:1
1%
100:1
1-5%c
Parking, longitudinal
5%
20:1
1%
100:1
1-3%c
a.
25% is the maximum slope for mowing
machinery.
b.
Slopes over 6% should have erosion protection.
c.
Accessible routes used by people with disabilities
shall conform to the criteria of Article 2, paragraph
2.4 of this Design Criteria.
Payload is drastically reduced on heavy trucks
*
sustaining grades over 3%. Ideal maximum
sustained grade for safe operation of trucks and
automobiles is 6%. On roads subject to frequent
icing and winter conditions the maximum
sustained grade is 5%.
VA Design Guide -- National Cemetery Administration
Page 5 -101
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