lecture notes of chapter five :
1- A circular curve is used to join two horizontal directions. The curve was widened to provide a suitable operation condition. The design speed on the curve=60km/hr, radius of the curve=80m, fs =0.15, design wheel base=6.1m
1- if the highway width at point (1)= 7m find the highway width at point( 2)
2-The figure shows a two lane highway in a hilly area. A rock located at a distance of 3m from the C.L of the inside lane obstructs the sight distance. If the radius to the C.L of the inside lane =40m, assuming a flat highway section, calculate the allowable speed on this section of the highway. ( coef. of friction=0.3, perception- reaction time=2.5 sec)
3- Prepare a setting out table to set out a spiral curve every 20m using the following data:
Length of spiral =100m. Radius of the circular curve= 400m
Station P.I = 20+00 (station of the intersection point between the two
tangents) Deflection angle between the two tangents =40º
4- Determine the minimum distance an object can be placed from the inside edge of a two lane flat highway without reducing the required stopping sight distance. The design speed=70km/hr, lane width=3.5 m, radius to the centerline of the highway=100m perception-reaction time= 2.5 sec, f=0.3
5- A horizontal curve of radius=100m is used to connect two tangents. The deflection angle between the tangents= 80˚ , station I= 20+15 ,
1- prepare a setting out table to set out the curve at points every ½ station.
2- If the design speed on the curve = 50 km/hr, fs =0.15, calculate the rate of superelevation on the curve.
6- C1 and C2 are two horizontal circular curves joined by a straight segment
Find stations PC1,PT1,PC2,PT2 .Find the length of the straight segment
Prepare a setting out table to set out the curve C1 every ½ station
An object is located at a distance of 2m from the C.L of the inside lane .What should be the design speed to provide minimum S.S.D
Assuming a horizontal highway segment. Lane width=3m
Complete the following sentences
1-low fill slope range=
2-shoulder slope range=
3-mountable curb height should be <
4-on motorways the maximum grade =
5-minimum grade on curbed pavement highway =
6-maximum length of spiral curve depends on…
8- A circular horizontal curve is used to connect two intersecting tangents.
The deflection angle between the tangents= 45˚, the length of the curve=400m.
1- prepare a setting out table to set out this curve at every 1/2 station.
2- if the elevation of point P.C=100m, elevation of P.T.= 108m and the curve
has uniform slope, calculate the elevations on this curve every ½ station.
3-In order to improve the alignment of this curve, a transition curve is
suggested. A shift value= 1.5 m is decided, calculate the required length
of this transition curve and find station TS.
9- State whether the following sentences are true or false. Correct the sentence if
1- when speed > 25km/hr, design is controlled only by the minimum turning path of the design vehicle.
2- best alignment is achieved when intersecting roads meet at an angle=40˚
3- when traffic light is used to control traffic the intersection is called interchange.
4- the traveled way on the horizontal curves are widened to increase the capacity
of the highway.
5- compound curves are used to change the alignment of the highway.
6- simple circular curves are used as vertical curves to connect two grades.
7-superelevations must be used at intersections inside towns.
10- a circular curve horizontal ramp is used to connect two intersecting highways. The deflection angle between tangents =50 degree.The length of the ramp=90m,superelevation rate=4% , fs =0.15, f=0.3,
perception reaction time = 2.5sec.
1- find the speed limit on this ramp.
11- A large object is located at a distance if 3m from the centre line of the inside lane of a horizontal curved section of a highway. This object affect the required stopping sight distance. The radius to the centre line of the inside lane=200m. Calculate the maximum speed on this highway to ensure safe crossing of pedestrians. Assume G=0
12-The figure shows a highway circular ramp connecting point A to B. The length of the ramp=235.62m. The superelevation rate =0.06, find:
a- the speed limit on this ramp