What is the passing sight distance for a section of 60 mile per hour (mph) 2-lane rural highway with a 1740-foot vertical sag curve where a bridge passes over at 16.8 feet? (Assume S L and A = 3.15)
A)870 feet
B)2,210 feet
C)2,273 feet
D)3,389 feet

Question

What is the passing sight distance for a section of 60 mile per hour (mph) 2-lane rural highway with a 1740-foot vertical sag curve where a bridge passes over at 16.8 feet? (Assume S > L and A = 3.15)
A)870 feet
B)2,210 feet
C)2,273 feet
D)3,389 feet

Quizplus · Accepted Answer

The passing sight distance for a section of 60 mph 2-lane rural highway with a 1,740-foot vertical sag curve where a bridge passes over at 16.8 feet is 2,273 feet.
Solution: Use sag vertical curve length at undercrossing equation (US Customary units)
S = L/2 + 400(C-5.75)/A
Where, L = 1740 feet
C = 16.8
A = 3.15
S = 1740/2 + 400(16.8-5.75)/3.15
= 2,273 feet

What Is the Passing Sight Distance for a Section of 60