Answer:
47 ft
Explanation:
Given parameters include;
The radius of the curve (R) = 1,100 ft
the mobile home is located at 12 ft ; this implies that the distance = 12 ft
Speed (V) = 65 mph = 104.65 kmph
Let assume that;
f = 0.35
t = 2.5 sec
The sight distance (SD) = [tex]0.275vt + \frac{v^2}{254f}[/tex]
= [tex](0.275*104.65*2.5)+\frac{104.65^2}{254*0.35}[/tex]
= 195.13 metre
= 195.13 × 3.28084
= 640.19 ft
However, if the length of the horizontal curve is greater than the sight distance ; then [tex]\frac{\alpha }{2}=\frac{130SD}{2 \pi (R-d)}[/tex]
[tex]\frac{\alpha }{2}=\frac{130*640.19}{2 \pi (1100-12)}[/tex]
[tex]\frac{\alpha }{2}=16.86[/tex]
The minimum setback distance (m) from the center of the center line is given as:
m= R - (R - d) cos [tex]\frac{\alpha}{2}[/tex]
m= 1100 - ( 1100- 12) Cos 16.86
m = 58.77 ft
m ≅ 59 ft
∴ the minimum distance from the centerline of the inside lane = 59 ft - 12 ft
= 47 ft
Thus, the minimum distance that mobile home needs to be far from the centerline of the inside lane so that a speed limit of 65 mph can be maintained = 47 ft
