By Pronob Ghosh 1204011 BUET

1. TRAFFIC SPEED
STUDY
PRONOB KUMAR GHOSH
STD ID: 1204011
DEPARTMENT OF CIVIL ENGINEERING,
BUET

2. OBJECTIVE
Capacity Studies
Economics Studies
 Accidental Analysis
Performance Study Of A Traffic Control Measures (Before And
After Studies)
Planning And Designing Traffic Control Measures Viz:
Traffic signal design
Designing road signs
Designing parking crossings
Establishing speed limits
Speed zoning
Placing speed breaker etc

3. TYPES OF TRAFFIC SPEED STUDY
1. Spot speed study: Instantaneous speed of a
vehicle at a point.
2. Travel time study: Speed measuring at
existing operating condition.

4. SPOT SPEED STUDY
• OBJECTIVE:
To find
Weighted average speed
Pace
Modal speed
Speed limits
Design speed

5. METHODS OF SPOT SPEED
MEASUREMENT
Manual method
44
ft

6. AUTOMATIC METHOD
1.Radar speed meter
2.Pressure strip method
3.Video Camera method
4.Tachometer

7. METHOD USED IN SURVEY
• Manual method
• Reasons: Manual method was used in this survey.
Because of lack of equipment automatic method was
not used though automatic methods are more
accurate.

8. SPEED HISTOGRAM
0
50
100
150
200
250
0-5 5-10 10-15 15-20 20-25 25-30 30-35
9
131
239
134
43
13 10
Frequency
Speed Range, mph
HistogramModal Speed 10-15 mph range

9. FREQUENCY DISTRIBUTION
0.00%
5.00%
10.00%
15.00%
20.00%
25.00%
30.00%
35.00%
40.00%
45.00%
0 5 10 15 20 25 30 35
FREQUENCY%
SPOT SPEED, MILE/HOUR
Freequency Curve
Modal Speed 12.5 mph
Pace 15 kMph

10. CUMULATIVE FREQUENCY CURVE OF SPOT
SPEED
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 5 10 15 20 25 30 35
CUMULATIVEFREQUENCY
Spot Speed, mph
Cumulative Frequency Distribution of Spot
Speed
85th percentile 16.5 mph
50th percentile 11
98 th percentile 26.5 mph

11. TRAVEL TIME
• Objective:
• To find
• Time mean speed
• Space mean speed
• Establish Wardrop Relationship
• Estimation of cost of delay

12. METHODS OF TRAVEL TIME
STUDY
1. Floating car method
2. Elevated observer method
3. License plate method

13. USED METHOD FOR SURVEY
• License plate method
• Reasons For using this method:
• Enables us to obtain travel time from a large sample,
that is helpful in understanding variability of travel
times among vehicles within traffic stream.
• Provides a continuous travel time during data
collection period and ability to analyze short time
periods.
• Data collection equipments are portable than others in
between observation sites.

14. CHI SQUARE TEST
Statistical hypothesis test where in
the sampling distribution of the test statistic is
a chi-squared distribution when the null
hypothesis is true.
Spot speed of CNG data is carried out to
analysis under chi-square test to get decision
where observed and expected vehicle meet
together or not.
As test static chi-squared value exceeds the
critical chi-square value 9.49 corresponding to
degrees of freedom, the null hypothesis is
rejected.

15. DELAY STUDY
Elapse time between the time required to
cover travel distance with free flow and the
time required to cover travel distance with
travel speed.
Average spot speed for each type of classified
vehicle is taken as free flow speed.
The percentage growth of delay cost is
assumed to be 7%.

16. BENEFIT –COST RATIO ANALYSIS
Ratio of the benefits of a project or proposal,
expressed in monetary terms, relative to its
costs.
Value of travel cost is taken as benefit
because if the delay is not occurred, then value
of travel cost will be added in national income.
Value of operating cost is taken as Cost.

17. LEVEL OF SERVICE
Qualitative measure used to relate the quality
of traffic service.
Used to analyze highways by categorizing
traffic flow.
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
0 0.2 0.4 0.6 0.8 1 1.2
Spacemeanspeed,mph
V/C ratio
Level of Service
F
A
B
C
D
E

18. THANK YOU