Traffic Engineering

1. TRAFFIC ENGINEERING
4/9/2018

2. TOPIC NAME: TRAFFIC STUDIES
SUBJECT CODE: 2I70613
BRANCH: CIVIL ENGINEERING
PREPARED BY:
GUIDED BY: PROF. RAJAN LAD
SR NO. NAME ENROLL. NO.
1. PATEL PRASHANT S. 141100106078
2. PATEL TWINKAL D. 141100106092
3. MISTRY ADITYA P. 151103106009
4. PATEL KAJAL M. 151103106011
5. RATNANI MANISHA N. 151103106016

3. CONTENT
• TRAFFIC STUDY
• WHEN SHOULD A TRAFFIC STUDY BE
CONDUCTED?
• TRAFFIC SURVEY
• TRAFFIC VOLUME STUDY
– AUTOMATIC COUNTING METHOD
– MANUAL COUNTING METHOD
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4. TRAFFIC STUDY
“A traffic study is a detailed examination
and analysis of a transportation system
supported by data collection.”
Source-Institute of Transportation Engineers

5. WHEN SHOULD A TRAFFIC STUDY BE
CONDUCTED?
• When a new development is proposed and it
will generate substantial new traffic;
• When financial assessments are implemented
(transportation impact fees);
• When a major roadway improvement or
reconstruction project is proposed;
• When a development is proposed for a
sensitive area.
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6. TRAFFIC SURVEY
• Traffic volume study
• Speed study
• Origin and destination study
• Traffic flow characteristics study
• Traffic capacity study
• Parking study
• Accident study
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7. TRAFFIC VOLUME STUDY
• Traffic volume studies are conducted to
determine the number, movements, and
classifications of roadway vehicles at a given
location.
• Volumes of a day or an hour can vary greatly,
depending on the different day of the week or
different time period of a day.
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8. METHODS OF
VOLUME STUDY
Automatically
Contact system
based
Contactless system
based
Manually
Direct Method
Indirect Method
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9. AUTOMATIC COUNTERS
• Automatic counters are also known as
mechanical counters .
• They can automatically record the total
numbers of vehicles crossing a section of the
road in desired period of time.
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10. AUTOMATIC COUNTERS
Advantages
• It can work throughout the
day and night for desired
period, which is impractical
in manual.
• No need of supervision.
• Suitable for long count.
Disadvantages
• It does not give the detail of
the traffic like various
classes, stream and turning
movement.
• It is not possible to record
pedestrian traffic.
• The impulses caused by
light vehicles may not be
enough in some cases to
acute the counter.
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11. AUTOMATIC COUNTING METHOD:
CONTACT SYSTEM
source-http://lgam.wikidot.com/traffic-counter
Pneumatic tube
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GDEC,CIVIL

12. AUTOMATIC COUNTING METHOD:
CONTACTLESS SYSTEM
Source-http://www.azcentral.com
Radar4/9/2018 12GDEC,CIVIL

13. AUTOMATIC COUNTING METHOD:
CONTACTLESS SYSTEM
• The other contactless method
– Photo-electric device
– Infra-red device
– Magnetic device
– Ultrasonic device
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14. MANUAL COUNTING METHOD
• The manually method is the method in which
a group of peoples are trained to record the
total numbers of vehicles crossing a section of
the road in desired period of time on record
sheets manually.
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15. MANUAL COUNTING METHOD
Advantage
• It gives the full detail of the
traffic like various classes,
stream and turning
movement etc of the
vehicles.
Disadvantage
• It cannot work throughout
the day and night for all
days of year.
• It is costly.
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16. MANUAL COUNTING METHOD:
DIRECT METHOD
Hand Counter
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17. MANUAL COUNTING METHOD:
INDIRECT METHOD
• Video cameras are mounted to record the
traffic condition on a road.
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18. MOVING OBSERVER METHOD
• Moving observer method of traffic stream
measurement has been developed to provide
simultaneous measurement of traffic stream
variables.
• It has the advantage of obtaining the
complete state with just four observers, and a
vehicle.
Source:-Dr. Tom V. Mathew, IIT Bombay
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19. MOVING OBSERVER METHOD
• Determination of any of the two parameters
of the traffic flow will provide the third one by
the equation q = uk
• Thus, moving observer method is the most
commonly used method to get the
relationship between the fundamental stream
characteristics.
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20. MOVING OBSERVER METHOD
AGAINSTWITH
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21. MOVING OBSERVER METHOD
Consider a stream of vehicles moving in the north
bound direction. Two different cases of motion can
be considered. The first case considers the traffic
stream to be moving and the observer to be
stationary. If No is the number of vehicles
overtaking the observer during a period of T ,then
N0 = q × T
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22. MOVING OBSERVER METHOD
The second case assumes that the stream is
stationary and the observer moves with speed V0. If
Np is the number of vehicles overtaken by observer
over a length L, then
Np = k × L
Np = k × V0 × T
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23. MOVING OBSERVER METHOD
Now consider the case when the observer is moving
within the stream. In that case Mo vehicles will
overtake the observer and Mp vehicles will be
overtaken by the observer in the test vehicle.
Let the difference M is given by Mo - Mp, then
M = Mo - Mp = q T − k Vo T
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24. MOVING OBSERVER METHOD
Mw = q Tw − k Vw Tw
Ma = q Ta + k Va Ta
the test vehicle is run twice once with the traffic
stream and another one against traffic stream, so
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25. )Ta(Tw
MaMwq


MOVING OBSERVER METHOD
From study;
q
yTwT 
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26. MOVING OBSERVER METHOD
The data from four moving observer test methods are
shown in the table. Column 1 gives the sample number,
column 2 gives the number of vehicles moving against
the stream, column 3 gives the number of vehicles that
had overtaken the test vehicle, and last column gives
the number of vehicles overtaken by the test vehicle.
Find the three fundamental stream parameters for
each set of data. Also plot the fundamental diagrams
of traffic flow. take length of stretch is 0.5 km and
journey time is 0.025.
Numerical Example
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27. MOVING OBSERVER METHOD
Sample no. X=no. of vehicle
moving against
traffic
Mo no. of vehicle
overtaking the test
vehicle
Mp no. of vehicle
overtaken by the test
vehicle
1 107 10 74
2 113 25 41
3 30 15 5
4 79 18 9
Samp
le no.
x mo mp y= mo
-mp
ta tw q v k
1 107 10 74 -64 0.025 0.025 860 5.03 171
2 113 25 41 -16 0.025 0.025 1940 15.04 129
3 30 15 5 10 0.025 0.025 800 40 20
4 79 18 9 9 0.025 0.025 1760 25.14 70
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28. MOVING OBSERVER METHOD
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29. PASSENGR CAR UNIT
• The different vehicle classes have a wide range of static
characteristics such as length, width, etc. and dynamic
characteristics such as speed, acceleration, etc. It is difficult to
estimate the traffic volume and traffic capacity of road way
under mix traffic flow.
• It is common practice to consider the passenger car as the
standard vehicle unit to convert the other classes vehicle
classes and this unit is called PCU.
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30. Factors affecting PCU
• Vehicle characteristics
• Traffic stream characteristics
• Roadway characteristics
• Control of traffic
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31. THANK
YOU
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