# High way lecture1

```High way and Transportation II (Lab.) LCIV 4034
Lecture 1
The course will contain the following:
1- Project: Geometric design of highway.
2- Laboratory experiments.
3- Discussion. (If required).
‫ما الفرق بٌن التصمٌم الهندسً و اإلنشائً للطرٌق؟‬
‫ هو التصمٌم الذي ٌهتم بتحدٌد عدد وعرض مسارب الطرٌق وكذلك تصمٌم مقاطع الطرٌق األفقٌة و‬:ً‫التصمٌم الهندس‬
.‫الرأسٌة و العرضٌة‬
‫ هو التصمٌم الذي ٌهتم بتحدٌد طبقات الرصف المناسبة للطرٌق وسماكة كل طبقة رصف بما ٌتناسب مع‬:ً‫التصمٌم اإلنشائ‬
.‫حجم المرور على الرصفة و خواص مادة الرصف‬


Introduction:

Definitions:
Speed: Rate of motion(mph, km/hr).
There are three types of speed:
-
Spot speed.
(‫) سرعة لحظٌة‬
It is the instantaneous speed of a vehicle at a specific location.
-
Running speed.
The average speed maintained over a given route while the vehicle is in motion.
-
Average Journey Speed.
Distance traveled divided by the total time taken to complete the distance.
Volume, Flow: The total number of vehicles that pass over a given point of high way during specific
time interval.
Rate of flow: the equivalent hourly rate at which vehicles pass over a given point of highway during a
given time period less than 1hour, usually 15min
Peak hour factor (PHF): the ratio of total hourly volume to the maximum 15-minute rate of flow
within the hour.
Peak hour factor (PHF) 
4  V15
volume during peak hour
(peak rate of flow within peak hour)
‫) كل المركبات تمر في ربع ساعة‬
PHF (minimum) = 0.25
( V = V15
PHF (maximum) = 1
( V=4V15 ‫ ) المركبات موزعة علي األرباع بالتساوي‬Steady flow
Example:
Time
volume
Rate of flow
6:00-6:15
375
375× 4=1500
6:15-6:30
380
1520
6:30-6:45
412
1648
6:45-7:00
390
1560
V=1557
PHF 
1557
 0.945  1
1648
Density, concentration: (K,D): the number of vehicles occupying a given length of highway at a given
instant. (Veh/km) ‫عدد السٌارات الموجودة فً طول معٌن من الشارع فً لحظة معٌنة‬
Level of Service: LOS is a qualitative measure that describes operational conditions within a traffic
stream and their perception by drivers or / and passengers.
Level of service has six levels, the first one is A, and the worst one in F.
What is the difference between LOS and Category of roads ?? (page 5)
ADT (average daily traffic): the average of 24hour counts collected over a number of days greater
than 1day and less than 1-year (‫ عدد هذه األيام‬/ ‫)مجموع السيارات خالل عدة أيام أقل من سنة‬.
AADT (average annual daily traffic): the average of 24-hour counts collected over a year.
It is used to:
1- Study The accidents and obstacles.
2- Design and evaluation of highway.
3- Study the benefits that may come from the road.
Number of Lanes Determination
.‫ تعتبر أول خطوة في تصميم الطريق‬.)‫ تعطي تحديد مبدئي لعدد المسارب (أثناء مرحلة التخطيط‬
Required Data:
1. General terrain through which the highway will pass. )‫(طبيعة األرض‬
o
Level terrain: )‫(مستوية‬
‫ال تحتوي منحدرات لذلك تستطيع الشاحنات الحفاظ علي سرعتها مثل المركبات األخرى‬
o
Rolling terrain: (‫)منحدرة‬
‫ميل األرض يسبب بطء للشاحنات لكن بدون ازدحام‬
o
Mountainous: )‫(جبلية‬
‫) ازدحاما‬H.V ) ‫انحدار عالي يسبب سرعة بطيئة نسبيا بذلك تسبب‬
2. AADT (the average annual daily traffic):
For the design year: n
(20-30) ‫سنة تصميمية‬
And growth rate of vehicles: i
(3-5)%
For the design
present
year
)‫العمر االفتراضي (عدد السنين‬
0.03 geometric growth
‫معدل الزيادة السنوية‬
3. The peak hour factor for the design year. PHF 
V
4V15
4. The percent of trucks.
5. The type of highway and environment. )‫(نوع الطريق المراد تصميمه‬
Type of highway: (divided or undivided)
)‫(وجود جزيرة أوال‬
Environment: (rural, suburban, urban)
6. The desired Level of service ( LOS )

)‫(الحالة التشغيلية للطريق‬
Computational steps:
1. Convert AADT (average annual daily traffic) to DDHV (Direction design hourly volume)
using:
(VPHPD) vehicle per hour per direction
K: the percent of AADT occurring in the peak hour.
D: the percent of AADT traffic in the peak direction. (One direction)‫معامل المسرب يحولها إلي‬
Type of environment
K (factor)
D (factor)
Urban
0.09-0.1
0.5
Suburban
0.1-0.15
0.6
Rural
0.15-0.2
0.65
2. Obtain service flow rate per lane (SFL)i in (veh/hr/lare) for the desired (LOS)
.‫) و نسبة الشاحنات و طبيعة البيئة‬LOS( ‫أقصي عدد من السيارات ممكن السماح له بالمرور في هذا المسرب و تعتمد علي‬
Service flow rate per lane for planning Applications (SFL)
Percent Trucks
LOS
0
2
4
5
6
8
10
12
15
20
Level Terrain
A
700
700
700
700
650
650
650
650
650
600
B
1100
1100
1050
1050
1050
1050
1000
1000
1000
1000
C
1400
1400
1350
1350
1350
1350
1300
1300
1250
1250
D
1750
1750
1700
1700
1650
1650
1650
1600
1600
1550
E
2000
2000
1950
1950
1900
1900
1850
1850
1800
1750
Rolling Terrain
A
700
650
600
600
600
550
550
500
500
500
B
1100
1050
1000
950
950
900
850
800
800
700
C
1400
1300
1250
1200
1200
1150
1100
1050
1000
900
D
1750
1560
1550
1500
1500
1400
1350
1300
1250
1100
E
2000
1900
1800
1750
1700
1600
1550
1500
1450
1250
Mountainous Terrain
A
700
600
550
500
500
450
400
400
350
300
B
1100
950
850
800
700
700
650
600
550
450
C
1400
1250
1100
1050
1000
900
850
750
700
600
D
1750
1550
1350
1300
1250
1100
1050
950
850
750
E
2000
1750
1550
1500
1400
1250
1200
1100
1000
850
3. Obtain (Fe): adjustment factor for development environment and type of multilane
highway.
Type
Divided
Un-divided
Rural
1
0.95
Urban Or Suburban
0.9
0.8
4. Calculate the required number of Lanes per direction.
N
DDHV
SFL f e  PHF
Example:
Given:
-Divided highway
-Rural environment
-PHF = 0.9
-Rolling terrain
-LOS = B
-% of trucks = 8%
- i=2%, n=20 years
Required:
-Number of Lanes N=?
Solution:
1.
(AADT) n = 9420 x (1+0.02)20 = 13998 vpd
2.
 0.15  0.2 
DDHV=13998× 
 × 0.65 =1593 (vph)
2


3.
Fe=1
4.
Find the SFL:
 LOS ( B)

Rolling Terrain
%trucks  8

5.


  SFL  900


Determine the number of lanes (N) in one direction:
DDHV
1593
N

 1.96  N  2lanes
SFL  Fe  PHF
900  1 0.9
(Use 4-lane multilane highway -2 lanes in each direction).
```