highway

1. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
EXERCISE NO.1
1- For a two lane highway with 3.5m lanes and for speed 80-90 km/hr range, find the
practical capacity in the following cases:
a) If the roadway has no features that limit capacity.
b) If 20% of the roadway has sight distance less than 450 m.
c) If obstructions are located within 1.5 m on both sides.
d) If the terrain is rolling and 10% of traffic is trucks.
2- What is the practical capacity per hour in one direction for 4-lane urban freeway in the
following cases:
a) If the roadway has no features that limit capacity.
b) If the terrain is level and the traffic is 20% trucks.
c) If during construction of an overcrossing. The roadway width is limited to 3 m lane
by piers supporting form work for the overcrossing.
3- For two lane rural road. The practical capacity is 900 passenger car per hour if the
roadway has no features that limit capacity and speed is 70-80 km/hr range. It is
required to determine:
a) The practical capacity where trucks make up 15% of the total traffic. In this case,
lane width is 3 m. with obstruction on one side within 0.5 m. of the roadway. The
road runs in rolling terrain.
b) Based on the 30th
hour principle, what average daily traffic can the road in
(a) accommodate?
4- A section of a rural highway in a rolling terrain is to be reconstructed to the best
standards for an operating speed of 80 mph. the expected A.D.T. during the design
year is 15000 vehicles in both direction with 20% trucks and 55% of traffic travel in
the main direction during peak hour. It is required to:
a) Determine the design speed hourly volume and the number of lanes required.
b) Draw a neat cross-section of the proposed highway passing partly through cutting
and partly trough filling. Give dimensions of all design elements.

2. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
Exercise No.2
1- a) A vehicle is travelling at 100 km/hr. assuming that driver perception time is 1.5 sec
and reaction time is 0.5 sec what will be his stopping sight distance on dry concrete
road with f=0.56, find also the sight distance one asphaltic road f=0.3.
2- a) Calculate the minimum passing sight distance required for 2-lane if the speed of
vehicle to be overtaken = 60 km/hr. assume any missing data.
b) Find the reduction in passing sight distance if the road consists of 3-lanes.
c) Draw the relation between passing sight distance and speed at 40, 50, 80 and 90
km/hr. the speed is the speed of the vehicle to be overtaken.

3. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
Exercise No.3
1- Determine the minimum vertical curve length to provide a safe sight distance in the
following cases:
Case Design speed (km/hr) Approaching grade Leaving grade
1 50 +5% -5%
2 65 -2% +4%
3 80 +2% -3%
4 100 -3% +3%
5 115 +3% 0.0%
2- A 1.5% grade tangent meets A -2.5% grade tangent at station 50+0.0 . A vertical curve
400 m long is used to connect the tangents. The elevation of the curve at sta. 48+0.0 is
25.0 m (one station = 50 m).
a) Find the station and elevation of the curve every 20 m.
b) Find the station and elevation of the H.P.
c) Should passing be allowed on this curve assuming a design speed of 80 km/hr.
3- Vertical curve is used to connect a +4% grade tangent with a -2% grade tangent.
Given the station of p.c. is 180+15 and the elevation of P.I. and H.P. is 36.5 m. and
35.9 m. respectively (station = 30 m).
a) Find the station of the highest point H.P.
b) Determine the maximum safe operating speed on the curve assuming perception
and reaction time 2.0 sec and coefficient of friction f = 0.32

4. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
Exercise No.4
1- Vehicle performance is being tested on a large paved area for the following situation:
a) What coefficient of side friction must be developed to speed 80 km/hr and D = 10
degrees.
b) What is the sharpest curve )stated in degree) that the vehicle travelling at 95 km/hr
if the coefficient of side friction is 0.14 and the maximum allowable super
elevation is 0.08.
2- A two lane of 3.75 m. traffic lane width, goes around a 8 degree curve, for a design
speed of 100 km/hr it is required to:
a) Compute the extra width required at the curve.
b) Compute the minimum length of transition curve.
c) Draw a plan showing the development of widening.
3- A corner of an existing obstruction is 6.0 m from centerline on 12 degree curved
portion of 2-lane roadway having a lane width of 3.0 m.
a) Considering horizontal sight distance along the centerline of the inside lane. What
is the safe operating speed?
b) If the desired operating speed is 100 km/hr, how far the obstruction should be set
back to satisfy the stopping sight distance.
4- The centerline of a 2-lane road 7.5 m. wide with a design speed of 80 mph runs along
a horizontal curve consisting of a circular curve and two transition curves. The road
has a cross slope of 1.5% and longitudinal slope = -1%. The tangent spiral point (T.S.)
has a station (215+0.0) and an elevation = 50 m. along the centerline. The circular
curve has a degree of curve = 8 degree and external angle = 80 degree. It is required
to:
a) Determine the length of the transition curve and the length of the circular curve.
b) Draw a neat sketch showing the attainment of super elevation along the curve, by
rotation about the inner edge, f = 0.17.
c) Calculate the station and elevation of the controlling points of the horizontal curve,
T.S., S.C., C.S. and S.T. at the centerline as well as the inside and outside edges of
the pavement.

5. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
Exercise No.5 & 6
EX. No. 5:
a) Find the H.R.B. classification for each soil listed in table “A”.
b) Find the group index for soils. Describe its probable behavior as subgrade.
EX. No. 6:
a) Find the unified classification for each soil listed in table “A”.
Table “A” tabulation of test results on ten soils
Test Soil Number
1 2 3 4 5 6 7 8 9 10
Sieve analysis
Total percent passing
(mm)
1.5 in. sieve (37.5) 100
1 in. sieve (25.4) 98
¾ in. sieve (19.0) 100 96 100 100
3/8 in. sieve (9.5) 73 85 100 96 100 99
No. 4 sieve (4.76) 100 100 60 60 99 100 89 99 98
No. 10 sieve (2.00) 94 94 50 47 80 94 81 95 100 97
No. 40 sieve (0.42) 70 21 24 44 70 61 92 95 94
No. 60 sieve (0.25) 57 80 15 18 36 55 50 80 88 93
No. 100 sieve (0.15) 42 78 10 12 26 42 40 68 81 90
No. 150 sieve (0.12) 58 74 9 11 20 38 35 62 75 88
No. 200 sieve (0.074) 32 70 8 10 18 31 29 58 67 86
No. 270 sieve (0.053) 24 62 2 10 25 20 52 60 75
Atterberg limits
Liquid limit 42 48 22 41 20 48 25 30
Plastic limit 30 18 17 36 17 36 14 21

6. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
Exercise No.7
1- Specimens of two soils were compacted in laboratory using the AASHO method. Unit
weight for varying moisture contents were as follows:
Soil No.1 Soil No.2
w/c% (Ib/ft³) Wet (Ib/ft³) w/c% (Ib/ft³) Wet (Ib/ft³)
4.42 134 12.5 122.5
6.75 144 14.2 125.0
7.35 145 16.2 128.5
8.36 145 17.0 128.5
8.93 144 19.7 127.5
a) Plot the wet density and dry density curves for these soils and determine the max. dry
density and optimum moisture content for each. Which of these soils is sand and
which is clay? Explain your answer.
b) Plot the zero air voids curve for each soil assuming that the specific of gravity of soil
particles is 2.68.
2- Compute the energy in foot-pounds per cubic foot of compacted soil in case of using
AASHO and modified.
3- The soil No.1 in problem (1) was compacted in field and the following date was
obtained:
Wt. of cubic foot of sand…………………………………….105 Ibs.
Wt. of soil removed from hole……………………………….5.8 Ibs.
Wt. of sand to fill the hole……………………………………4.5 Ibs.
Moisture content of soil removed from hole..………………..15.5%.
Determine the relative compaction and comment on your answer.

7. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
4- A mixture of soil (30%) and aggregate (70%) compacted at 100% of max. dry density.
Soil: = 2.72 L.L. = 50 P.L. = 20
Aggregate: = 267 absorption = 6%
Mixture: Max dry density = 130 pcf. Opt. moisture content = 8.5%
Find the moisture content of total mixture and the soil fraction only assuming only
obstructed moisture distributed to the aggregate when all voids are filled with water
(case of saturation).
5- A clayey soil of max. dry density 130Ib/ft³ in the laboratory was compacted in the
field by means of rollers. A cylindrical specimen measuring 4 inches diameter and 5
inches height was taken after each pass. The following data was obtained:
No. of passes 1 2 3 4 5
Weight of specimen (Ib.) 4.4 4.5 4.75 4.94 5.3
w/c % 12 13 12 10 11
a) Determine the number of passes required for the proposed compaction 95%.
b) Determine the volume of compacted materials in cubic meter per hour if the width
of the roller 2.25 m. thickness of compacted layer 15 cm.
velocity of roller 15 km/hr and efficiency considering weather and other factors is
0.6.

8. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
Exercise No.8
1- A subgrade soil exist in a depressed area with a depth of 5.0 ft and ground water table
is at about 2.0 ft below the surface.
Indicate by means of sketches the type of subdrainage system you propose for 2-lane
pavement showing all important features of design. Give the grain size distribution of
filter material you specify for back-fill for around drainage pipe.
2- Data taken during a C.B.R. test is as follows:
Load on piston (Ib.) Penetration (in.) Load on piston (Ib.) Penetration (in.)
15 0.05 27 0.075
51 0.1 81 0.125
120 0.15 150 0.175
174 0.2 192 0.25
201 0.3 210 0.35
222 0.4 240 0.5
a) What is the C.B.R. of the soil?
b) Determine the surcharge weights which are required for C.B.R. test on a soil if the
estimated pavement thickness will be 20 inches. The pavement will have a unit
weight of 150 pcf.
3- 30-in. plate loading test performed on subgrade soil, and on a 12 inches base coarse
yielded the results shown below:
Deflection (in) 0.01 0.03 0.05 0.06 0.08 0.10
Load in Ib (subgrade) 3532 8100 11330 12010 13423 14130
Load in Ib (12ʺ base) 5652 12717 17662 20135 24757 28260
a) Determine the modulus of subgrade reaction of the soil and the soil-base course
combination.
b) Develop an expression for modulus of subgrade reaction (K) in terms of the modulus
of elasticity (E) as determined by plate bearing test.
4- A drained triaxial test is made on a sand sample to failure. The confining stress is 20
psi. the vertical stress at failure (deviator stress) is 45 psi.
a) By means of Mohr diagram, find the approximate angle of internal friction.
b) The approximate vertical load at failure, if the lateral confining pressure is 10 psi.
and the diameter of sample is 2 inches.

9. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
Exercise No.9
1- Determine the thickness of base and subbase course required for an asphalt pavement
suitable for a wheel load of 12000 Ib if the subgrade soil has a C.B.R. value 3% and
the subbase having a C.B.R. value of 16%. The wearing surface is asphaltic 2 inches
thickness.
2- A new highway is to traverse an area for which the native soil corresponds to No. 2 of
table “A”, this soil will be the subgrade and will be used for embankments. A select
material like soil No.5 table “A” may be used as subbase. Soil No.8 shall be used as
course. Surface course shall be 3 inches bituminous concrete and A.D.T. is 1000
vehicles with 10% of vehicles are trucks. For the given data, develop typical pavement
cross-section showing the depth of each individual layer to the nearest half inch.
3- A plate loading test using a 30-inch diameter rigid plate was made on a subgrade as
well as on 10 inches of gravel base course.
The unit load required to cause settlement of 0.2 inch was 10 and 40 psi
respectively. Determine the required thickness of the pavement to carry a single
wheel load of 50000 Ib with 100 psi tire pressure.
4- a) determine the thickness of base course in flexible pavement to support a
design wheel load of 9000 Ib with a tire pressure of 80 psi. given that:
allowable deflection = 0.1ʺ
thickness of surface course = 2ʺ
traffic coefficient =1.0
saturation coefficient = 1.0
modulus of elasticity of subgrade, base course and surface course = 1500,
5880,15000 psi respectively.
b)If it would be desirable to use a subbase of an available gravel material having
modulus of elasticity 3740 psi and assume = 6ʺ
T = (

10. Tanta university
Faculty of Engineering Highway Engineering
Public Works Dept. 4th
year civil
2010/2011
Prof. Dr. Mohamed Hafez Fahmy Aly
Head of Transportation Engineering Dept
Faculty of Engineering - Alexandria University
Exercise No.10
1- Determine the equivalent single wheel load for dual-tandem gear carrying 100000 Ib
with contact pressure 100 psi and spaced 20 x 40 inches if the thickness of the
pavement equal 10 inches
2- If the allowable flexural stress in paving concrete is 350 psi, the pavement is designed
for 12000 Ib wheel load.
It is required to determine:
a) The pavement thickness if the subgrade is poor so that “k” the coefficient of
subgrade reaction equals 50.
b) The pavement thickness if the subgrade is excellent so that k=500.
3- The flexural strength in paving concrete is 650 psi, the pavement is designed for
10000 Ib wheel load, determine:
a) The pavement thickness if the modulus of subgrade reaction equals 75.
b) The pavement thickness if the modulus of subgrade reaction equals 500.
c) If a base course 12 inches is required to bring this improvement in “k” value, is it
justified from a cost standpoint?
Assume that paving concrete costs 120 Egyptian pounds per cu.m., and base course
costs 50 E.P./cu.m. (both prices complete in place)
4- Determine the required area of distributed steel reinforcement and tie bar steel for a
pavement 12 by 40 ft. and 10 in. thickness for the following condition:
Weight of concrete = 150 Ib/ft³
Coefficient of friction = 1.5
Allowable tensile stress in steel = 22000 psi