Question

5. A crest vertical curve of a highway segment is designed to connect upgrades of 5 percent while the downgrade on the other side is 3 percent. What's the minimum length of the curve for adequate stopping sight distance if the stopping sight distance is 400 ft for the design speed is 45 mph and drives' eye height is 3.5 ft and the object height 2.0 ft? A. 430 B. 493 C. 593 D. 530

Answer 1

General equations for length of ventical Cunne when L>s L = AS² 2 100 Jah, +12h2 when L<s, L = 25- 2005h, the 2 А h = height of eye where L = Length of vertical Curve [ft] S = Stopping sight distance [ft] = 400ft above roadway [ft] = 3.5 ft h₂ = height of object above roadway [ft] = 2.oft A = algebraic difference in grades [%] - (G, -G] 4. G, = upword grade = [5-(-3) - 15% 8./. G2 - downward grade --3%

Let us assume L>s, then AS² 100 [52h, +52h2 2 (8) (400)2 100 [12 (3.5) +1262) 2 L = 593.o5 ft 1 2 2 543 L =593ft Since "L" is greater than "s" our assumption is Connect Minimum length of curre, L = 593ft

Answer: option C (593 ft)