Of the following, which is the approximate optimal length for a transitional spiral curve when using a 2,500 ft circular curve and a design speed of 65 mph?
A)50 ft
B)100 ft
C)175 ft
D)200 ft

Question

Quizplus · Accepted Answer

The approximate optimal length for a transitional spiral curve when using a 2,500 ft circular curve and a design speed of 65 mph is 175 ft. Solution Use the transitional spiral curve formula: L = 1.6 (design speed)< sup> 3< /sup> / radius of the circular curve Where design speed = 65 mph radius of circular curve = 2,500 ft L = 1.6 (65 mph)< sup> 3< /sup> / 2500 ft = 176 ft (use 175 ft)

Of the Following, Which Is the Approximate Optimal Length for a Transitional