Traffic speed study
Ahmed Ferdous1004137
Department of civil engineeringBangladesh University of Engineering and Technology
Objective
• Determine weighted average speed, Pace, modal speed, speed limits, design speed
• Check the speed distribution pattern• Finding Time-mean speed and Space-mean speeds • Finding delay for each type of vehicle • Finding the cost of delay• Find LOS of study road
IMPLICATION• Capacity studies • Geometric studies • Accident analysis • Economic studies • Performance studies • Planning and designing of
1. Traffic signal design 2. Road sign design 3. Parking crossing design 4. Establishing speed limit 5. Speed zoning 6. Placing control device
Methodology
SPOT SPEED:1.Manual2.Automatic: a. RADAR meter
b.Pressure strip c.Video
d.Graph
Travel speed: a.License plate method
b.Floating car method c.Elevated observer method
OUR APPROACHSPOT SPEED : MANUAL odometer , stopwatch Checking with radar gun Grouped numerators
Travel speed :License plate methodMobile phone , recording app,stopwatch
Data collection:
Data Analysis:Flow Histogram:
5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.000
5
10
15
20
25
30
35
40
45
%frequency vs speed histogram
Series1
spot speed,mph
%fr
eque
ncy
• maximum vehicle varies speed between 15-20 mph.About 40%.
• Velocity less than 10mph is very rare.
• Very few vehicle are within speed greater than 35mph
Frequency Curve:
0 5 10 15 20 25 30 35 400
5
10
15
20
25
30
35
40
45
spot speed,mph
% fr
eque
ncy • Modal speed 16 mph for this
road and traffic condition.• Pace is in between 9mph and
24mph.• As the curve is nearly
symmetric, so Median speed is also 16mph
Average speed:
speed mid speed frequency %frequency v total
0 to 5 2.5 0 0 0
5 to 10 7.5 1 0.653595 7.5
10 to 15 12.5 58 37.9085 725
15 to 20 17.5 61 39.86928 1067.5
20 to 25 22.5 22 14.37908 495
25 to 30 27.5 6 3.921569 165
30 to 35 32.5 5 3.267974 162.5
35 to 40 37.5 1 0.653595 37.5
154 100 total 2660
Vehicle are running at a speed of 17.27mph
Cumulative frequency distribution:
0 5 10 15 20 25 30 35 400
20
40
60
80
100
120
Axis Title
Axis Title
95%85%50%15%
Our design speed to be 32.5mph
Median speed is 16 mph.Look it has satisfied the previous %frequency vs speed curve
Safe speed is 19mph Speed limit is 9mph to 19
mph
Travel Speed :
Vehicle Type
Vehicle No Duration (Seconds)
Speed (m/s)
Average Duration (Seconds), dT1
Car 1 140 7.14286
160.80
2 155 6.451613 150 6.666674 183 5.464485 176 5.68182
Bus 1 251 3.98406
241.752 228 4.385963 262 3.816794 226 4.42478
CNG 1 217 4.60829
215.502 245 4.081633 197 5.076144 203 4.92611
Motorcycle
1 318 3.14465
289.202 223 4.48433 329 3.039514 297 3.3675 279 3.58423
Travel Time
On average• Time mean speed 4.5
min• Space mean speed
2.5sec
10
1
2
3
4
5
6
time mean speed and space mean speed
time mean space mean
duration
speed time mean speed
space mean (ʋi- ʋt)^2 sd space mean+sd62/space mean
179 4.469274 4.829396 2.556784 0.129688 5.787736 3.9987
110 7.272727 52.89256
105 7.619048 58.04989
106 7.54717 56.95977
150 5.333333 28.44444
285 2.807018 7.879347
98 8.163265 66.6389
94 8.510638 72.43096
109 7.33945 53.86752
50 16 256130 6.153846 37.86982
135 5.925926 35.1166
1019 0.785083 0.616356
137 5.839416 34.09878
144 5.555556 30.8642
144 5.555556 30.8642
158 5.063291 25.63692
153 5.228758 27.33991
247 3.238866 10.49026
215 3.72093 13.84532
The war drop relationship is established
Delay cost:
no delay
total delay ,min
voc facor
occupancy fact
vot factor
cost 1
passenger
cost 2
total
lv 4001
60.8
67.57244
100
2.1 20 6757.244
8402.1 168042
174799.2
ar 917
40.5
10.31625
25 2.1 5 257.9063
1925.7 9628.5
9886.406
sp 833
40.4
9.348111
45 10 6 420.665
8330 49980
50400.67
truck
83 95 2.190278
176
0 0 385.4889
0 0 385.4889
bus
166
91.75
4.230694
110
40 5.52
465.3764
6640 36652.8
37118.18
bike
833
109.2
25.26767
5 1 12 126.3383
833 9996 10122.34
So we can see per hour cost of in total is about 282712 BDT
Most loss is done for light vehicle passengers
Distribution pattern:
Value of chi square is 29.9
LEVEL OF SERVICE:
DATA shows it to be F
But• Visual seems to be los C• This is due to that we
assumed to be lane wise and motorized vehicle which is not the real situation
LEVEL OF SERVICE:
DATA shows it to be F
RECOMMANDATION:
For improvement • We have found speed to be
decreased due to loss of width which is the result of unauthorized parking. So improvement can be done here.
• Service road within or controlled entrance from nearby estates has to be done
For Study:• If speed gun and
wireless talking device(travel speed) were used more frequently more reliable data could be gained. Some group used it un evenly. If equitable use were done data would be more correct
• A test survey should be conducted first
SUMMARY:• maximum vehicle varies speed between 15-20 mph.About 40%.• Again volume study showed about 50% vehicle was light vehicle.So a
summary can be taken as light vehicle are running at a speed near 20 mph in that section
• Modal speed 16 mph for this road and traffic condition.That is most car want to maintain 16mph while operating
• Pace is in between 9mph and 24mph.That is most driver are seen with 15 mph difference , to be in between these speeds
• As the curve is nearly symettric,so Median speed is also 16mph • Our design speed to be 32.5mph• Median speed is 16 mph.Look it has satisfied the previous %ferquency vs
speed curve• Safe speed is 19mph• Speed limit is 9mph to 19 mph• Space mean speed is 2.5mph and time mean is 4mph• Visual seems to be los CT
Question?
THANK YOU