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