Table D-5
Sight Distance (Metric)
Design Speed Stopping Sight Distance Minimum K Values Passing Sight Distance
(km/h) (meters) (meters) (meters)
Desirable Minimum Crest Curve Sag Curve For 2-lanes
30 30 29.6 3 4 *
50 70 57.4 9 11
*
60 90 74.3 14 15 *
90 170 131.2 43 30 *
100 210 157.0 62 37 *
Nole: General practice calls for vertical curves to be multiples of 1 meters. Calculated lengths
shall be rounded up in each case. *Minimum passing distance for 2-lanes is currently under
revision. (Reference NCDOT Roadway Metric Design Manual page 1-12 T-l)
'K is a coefficient by which the algebraic difference in grade may be multiplied to determine
the length of the vertical curve which will provide the desired sight distance. Sight distance
provided for stopped vehicles at intersections should be in accordance with "A Policy on
Geometric Design of Highways and Streets. 1990".
Table D-6
Superelevation (English)
Design Speed Minimum Radius of Maximum e 1 Maximum Degree of Curve
(mph) e=0.04 e=0.06 e=0.08 e=0.04 e=0.06 e=0.08
30 302 273 260 19 00" 21 00' 22 45'
60 573 521 477 10 00' 11 15' 12 15'
80 955 955 819 6 00" 6 45" 7 30'
100 1,637 1,432 1,146 3 45' 4 15' 4 45'
'e = rate of roadway superelevation, foot per foot
No,e (Reference NCDOT Roadway Design Manual page 1-12 T-6 thru T-8)
Table D-7
Superelevation (Metric)
Minimum Radius of Maximum e 1
Design Speed e=0.04 e=0.06 e=0.08
50 100
65 175
80 280
100 490
90 80
160 145
250 230
435 395
L _
e = rate of roadway superelevation, meter per meter.
D7