A horizontal curve is being designed for a new four-lane roadway with 11-ft lanes. The PT is located at station 1050+20, the design speed is 45 mph and maximum superelevation of 4%. If the central angle of the curve is 30 degrees, what is the radius of the curve and location of the PC and PI?

Traffic and Highway Engineering
5th Edition
ISBN:9781305156241
Author:Garber, Nicholas J.
Publisher:Garber, Nicholas J.
Chapter15: Geometric Design Of Highway Facilities
Section: Chapter Questions
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Example Prob Below:
A horizontal curve is being designed for a new three-lane roadway with 12-ft lanes. The PT
is located at station 35+70, the design speed is 60 mph and maximum superelevation of 6%.
If the central angle of the curve is 25 degrees, what is the radius of the curve and location
of the PC and PI?
3-lane roadway: 12ft lanes;
PT=35+70; V = 60mph=88fps;
emax 0.06; A= 25°
Find:
Solution:
From Table 3.5, for V = 60-f₂ = 0.12
Ry
Ry=-
R
R, PC, PI
V²
88²
g(e+f) 32.2(0.06 +0.12)
=
=1336.1ft
R = R₁ +12= 1336.1 + 12 = 1348.1ft
L = RA= (1348.1) (25) 588.2ft
180
180
PC = PT-L = (35+70) - (5+88.2) -29+81.8
Δ
T =R x tan=1348.1 x tan
PI = PC + T = (29+81.8)+(2+98.8)=32 +80.6
(²³) = 298.8ft
Transcribed Image Text:Example Prob Below: A horizontal curve is being designed for a new three-lane roadway with 12-ft lanes. The PT is located at station 35+70, the design speed is 60 mph and maximum superelevation of 6%. If the central angle of the curve is 25 degrees, what is the radius of the curve and location of the PC and PI? 3-lane roadway: 12ft lanes; PT=35+70; V = 60mph=88fps; emax 0.06; A= 25° Find: Solution: From Table 3.5, for V = 60-f₂ = 0.12 Ry Ry=- R R, PC, PI V² 88² g(e+f) 32.2(0.06 +0.12) = =1336.1ft R = R₁ +12= 1336.1 + 12 = 1348.1ft L = RA= (1348.1) (25) 588.2ft 180 180 PC = PT-L = (35+70) - (5+88.2) -29+81.8 Δ T =R x tan=1348.1 x tan PI = PC + T = (29+81.8)+(2+98.8)=32 +80.6 (²³) = 298.8ft
A horizontal curve is being designed for a new four-lane roadway with 11-ft lanes. The PT
is located at station 1050+20, the design speed is 45 mph and maximum superelevation of
4%. If the central angle of the curve is 30 degrees, what is the radius of the curve and
location of the PC and PI?
Transcribed Image Text:A horizontal curve is being designed for a new four-lane roadway with 11-ft lanes. The PT is located at station 1050+20, the design speed is 45 mph and maximum superelevation of 4%. If the central angle of the curve is 30 degrees, what is the radius of the curve and location of the PC and PI?
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ISBN:
9781305156241
Author:
Garber, Nicholas J.
Publisher:
Cengage Learning