Two vertical parabolic curves have been connected to form a roadway by three gradients: -5.30 %, 4.10 % and -3.70 % respectively. If the length of the second curve is twice as the length of the first curve, compute the following: a. The length of the second curve in ft given that the design speed of the first curve is 80 kph assuming a vertical radial acceleration of 0.3m/s2 for comfort criterion. b. The length of the second curve in m if the headlight height of the vehicle is 0.73 m above the first curve and the inclined upward angle of the headlight beam relative to the horizontal plane of the vehicle is 1.57% The design speed for the first curve for this situation is 90 kph. c. The length of the first curve in yard if the total length of the roadway is 7451 m given that the second curve has a design speed of 70 kph for passing sight distance with the driver's eye height assumed to be 1.5 m and object height of 0.33 m.
Two vertical parabolic curves have been connected to form a roadway by three
gradients: -5.30 %, 4.10 % and -3.70 % respectively. If the length of the second
curve is twice as the length of the first curve, compute the following:
a. The length of the second curve in ft given that the design speed of the first
curve is 80 kph assuming a vertical radial acceleration of 0.3m/s2 for
comfort criterion.
b. The length of the second curve in m if the headlight height of the vehicle is
0.73 m above the first curve and the inclined upward angle of the headlight
beam relative to the horizontal plane of the vehicle is 1.57% The design
speed for the first curve for this situation is 90 kph.
c. The length of the first curve in yard if the total length of the roadway is 7451
m given that the second curve has a design speed of 70 kph for passing sight
distance with the driver's eye height assumed to be 1.5 m and object height
of 0.33 m.
d.The total length of the roadway in km if a bridge structure were to be
located within the first curve, with a required clearance height of 6.25 m,
then assuming a driver's eye height of 3.4 m and an object height of 0.31 m
if the design speed is 130 kph.
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