Faculty:
Faculty of Civil and Environmental Engineering Department :
Department of Geotechnical and Transportation Engineering Title:
SPOT SPEED STUDY
1.0 INTRODUCTION
Speed is the rate of movement of a vehicle, generally expressed in kilometers per hour.
A spot speed study is a study of traffic speed at one point or spot on a traffic way. It consists of a series or a sample of observations of the individual speeds at which vehicles are approaching an intersection or passing a point at a non-intersection location. These observations are used to estimate the speed distribution of the entire traffic stream at that location, under the conditions prevailing at the time of the study.
Spot speed studies can be used to study speeds at problem locations in order to determine whether speeds are too high and if complaints received are justified, for accident analysis in order to determine the relationship of speed to accidents which may help in developing corrective measures, and for before-and-after studies in order to evaluate the effect of some change in controls or conditions.
In relation with this study, there has been several complaints of vehicles speeding along the UTHM-Fujitsu section of road. This poses a danger to motorists, pedestrians and cyclists as there is a lot of activity in the area. Furthermore, there are plenty of right-turning movements along this stretch of road, with no storage lanes provided for right-turners. This is dangerous because the right-turners stop on the fast lane and have no protection.
2.0 OBJECTIVE
The objectives of this study are:
(a) To determine the speed characteristics of traffic at the location. (b) To justify the problem of speeding at the location.
3.0 APPARATUS
1. Radar Gun
2. Forms SS1 and SS2 3. Graph Paper (3 nos) 4. Safety Vest
Faculty:
Faculty of Civil and Environmental Engineering Department :
Department of Geotechnical and Transportation Engineering Title:
SPOT SPEED STUDY 4.0 PROCEDURE
1. The spot at which the speed data will be collected is indentified.
2. The radar gun to measure the speed of vehicles is used according to their respective vehicle class – Class 1 (Motorcycles), Class 2 (Cars), Class 3 (Vans & Medium Trucks), and Class 4 (Large Trucks & Buses).
[Make sure that the operator of the radar gun is not seen by the motorists] 3. All speed measurements recorded in Form SS1.
4. Based on Form SS1, determine the mean, maximum and minimum speed of vehicles according to their class. Your findings are commented.
5. The data is transferred in Form SS1 to Form SS2.
6. The following are plotted:
(a) Frequency Histogram (Percentage of vehicles vs. Speed) (b) Frequency Distribution Curve (Percentage of vehicles vs. Speed)
(c) Cumulative Frequency Distribution Curve (Cumulative percentage vs. Speed)
7. The following speed characteristics is determined: (a) Mean speed
(b) Median speed (c) Mode speed
(d) 85-th Percentile speed (e) Standard deviation (f) Pace
5.0 DATA ANALYSIS & RESULT
Form SS1
Location: Jejantas Parit Jelutong (Ayer Hitam to Batu Pahat) Day: Monday Date: 10January 2011 Time: 3.00 pm Weather: Fine
Time Spot Speed (km/h)Vehicle Class
1 2 3 4 (3.00 -3.15) pm 22 44 50 44 34 43 31 41 44 40 33 45 56 38 47 44 34 43 41 37 64 36 43 53 34 50 14 37 33 47 41 86 66 40 41 30 26 53 77 48 32 45 36 44 64 34 63 38 15 67 13 38 32 47 47 64 77 24 58 84 (3.15 -3.30) pm 42 60 54 42 48 62 46 57 79 41 19 71 32 57 30 30 43 50 33 37 38 46 41 71 28 49 69 48 25 47 36 41 44 37 49 62 22 52 91 50 44 48 36 40 32 34 78 68 26 55 46 56 32 63 28 38 61 33 31 71 (3.30 -3.45) pm 46 30 58 37 45 42 35 36 70 25 33 42 38 32 47 41 30 52 11 40 77 71 44 62 42 62 63 42 37 35 40 59 79 43 38 43 61 45 22 49 46 30 45 35 38 45 62 54 26 26 78 38 38 53 53 48 42 35 64 61 (3.45 -4.00) am 21 57 44 29 51 49 46 72 86 36 33 68 48 46 11 38 44 53 45 78 48 33 39 36 36 25 70 40 40 18 43 80 65 37 36 63 30 49 36 46 51 77 33 92 66 43 35 66 58 27 10 40 42 60 68 66 72 52 41 60
Faculty:
Faculty of Civil and Environmental Engineering Department :
Department of Geotechnical and Transportation Engineering Title:
SPOT SPEED STUDY
SPEED CLASS (km/h) Number of Vehicles Vehicles Class Total 1 2 3 4 10 – 14 4 1 5 15 - 19 1 1 1 3 20 - 24 4 1 5 25 - 29 7 2 1 1 11 30 - 34 5 7 2 8 22 35 -39 4 9 12 9 34 40 - 44 4 15 12 11 42 45 - 49 9 13 6 6 34 50 - 54 7 7 2 4 20 55 - 59 5 2 2 2 11 60 - 64 4 3 5 6 18 65 - 69 2 5 5 12 70 - 74 1 3 5 9 75 - 79 2 1 5 8 80 - 84 1 1 2 85 - 89 2 2 90 - 94 1 1 2 Note:
Vehicles class 1: Motorcycles Vehicles class 2: Cars
Vehicles class 3: Vans and medium trucks Vehicles class 4: Heavy trucks and buses
Speed Class (km/h) Class Midpoint, x (km/h) Class Frequency, f fx Percentage in Class, (%) Cumulative Percentage (%) 10 – 14 12 5 60 2.08 2.08 15 - 19 17 3 51 1.25 3.33 20 - 24 22 5 110 2.08 5.41 25 - 29 27 11 297 4.58 9.99 30 - 34 32 22 704 9.17 19.16 35 -39 37 34 1258 14.17 33.33 40 - 44 42 42 1764 17.5 50.83 45 - 49 47 34 1598 14.17 65 50 - 54 52 20 1040 8.33 73.33 55 - 59 57 11 627 4.58 77.91 60 - 64 62 18 1116 7.5 85.41 65 - 69 67 12 804 5 90.41 70 - 74 72 9 648 3.75 94.16 75 - 79 77 8 616 3.33 97.49 80 - 84 82 2 164 0.83 98.32 85 - 89 87 2 174 0.83 99.15 90 - 94 92 2 184 0.83 99.99 ∑n = 240 ∑= 11215 ∑= 100
Speed Class (km/h) Class Midpoint, x (km/h) Class Frequency fn.x f1 f2 f3 f4 f1.x f2.x f3.x f4.x 10 – 14 12 4 1 48 12 15 - 19 17 1 1 1 17 17 17 20 - 24 22 4 1 88 22 25 - 29 27 7 2 1 1 189 54 27 27 30 - 34 32 5 7 2 8 160 224 64 256 35 -39 37 4 5 12 9 148 185 444 333 40 - 44 42 4 15 12 11 168 630 504 462 45 - 49 47 9 13 6 6 423 611 282 282 50 - 54 52 6 7 2 4 312 364 104 208 55 - 59 57 5 2 2 2 285 114 114 114 60 - 64 62 4 3 5 6 248 186 310 372 65 - 69 67 2 5 5 134 335 335 70 - 74 72 1 3 5 72 216 360 75 - 79 77 2 1 5 154 77 385 80 - 84 82 1 1 82 82 85 - 89 87 2 174 90 - 94 92 1 1 92 92 60 60 60 60 2538 2462 3145 2870 Mean speed
n
f
x
i. Class 1: Motorcycles iii. Class 3: Vans and medium trucks
hr km n f / 3 . 42 60 2538 1 1 hr km n f / 42 . 52 60 3145 1 1
ii. Class 2: Cars iv. Class 4: Heavy trucks and buses
hr km n f / 03 . 41 60 2462 1 1 hr km n f / 83 . 47 60 2870 1 1
Faculty:
Faculty of Civil and Environmental Engineering Department :
Department of Geotechnical and Transportation Engineering Title:
SPOT SPEED STUDY 6.0 CALCULATION & RESULT
(1).
i. Class 1: Motorcycles iii. Class 3: Vans and medium trucks
Mean speed = 42.3 ≈ 42 km/hr Mean speed = 52.42 ≈ 52 km/hr Maximum speed = 91 km/hr Maximum speed = 92 km/hr
Minimum speed = 10 km/hr Minimum speed = 11 km/hr
ii. Class 2: Cars iv. Class 4: Heavy trucks and
buses
Mean speed = 41.03 ≈ 41 km/hr Mean speed = 47.83 ≈ 48 km/hr Maximum speed = 77 km/hr Maximum speed = 84 km/hr
Minimum speed = 18 km/hr Minimum speed = 19 km/hr
Comment:
From the data, we obtained the mean speed, maximum speed and the minimum speed for motorcycles, cars, van and medium trucks and heavy trucks or buses. We are noticed that the mean speed for class 1 (Motorcycle) is 42 km/hr, class 2 (Cars) is 41 km/hr, class 3 (Vans & medium Trucks) is 52 km/hr and class 4 (Heavy trucks and Buses) is 48 km/hr. the highest mean speed is car which is 52 km/hr. It has shown that many vehicle are obey the speed limit which is 60 km/hr. However, the vans and medium trucks have the highest of maximum speed. It was dangerous for all either motorist, pedestrians and cyclist. 48 heavy vehicles and maybe more than that was trough along UTHM – Fujitsu section of road for one hour. No protection and storage lane provides can influence the accident occur.
(2).
(a) Mean speed:
hr km n f speed mean x / 73 . 46 240 11215 (b) Median speed: hr km C f f n L speed median m L / 21 . 44 5 34 122 2 240 5 . 44 2
(c) Mode speed: (60 – 64) km/hr which 44 vehicles (refer at graph 2)
(d) Standard deviation: hr km hr km n n f n fx x / 14 2 5 . 6 4 5 . 4 7 2 P P deviation standard Estimate / 37 . 49 ) 1 240 ( 240 ) 11215 ( 1 240 582775 ) 1 ( ) ( 1 deviation Standard 15 85 2 2 2
Faculty:
Faculty of Civil and Environmental Engineering Department :
Department of Geotechnical and Transportation Engineering Title:
SPOT SPEED STUDY
Faculty:
Faculty:
Faculty of Civil and Environmental Engineering Speed Class
(km/h) Lower limit (km/hr) Class frequency,f Cumulative classfrequency
10 – 14 9.5 5 5 15 - 19 14.5 3 8 20 - 24 19.5 5 13 25 - 29 24.5 11 24 30 - 34 29.5 22 46 35 -39 34.5 34 80 40 - 44 39.5 42 122 45 - 49 44.5 34 156 50 - 54 49.5 20 176 55 - 59 54.5 11 187 60 - 64 59.5 18 205 65 - 69 64.5 12 217 70 - 74 69.5 9 226 75 - 79 74.5 8 234 80 - 84 79.5 2 236 85 - 89 84.5 2 238 90 - 94 89.5 2 240 L fL fm
Department :
Department of Geotechnical and Transportation Engineering Title:
SPOT SPEED STUDY
Faculty:
Faculty of Civil and Environmental Engineering MEDIAN SPEED Speed Class (km/h) Class Midpoint, x (km/h) x2 Class frequency, f fx fx2 10 – 14 12 144 5 60 720 15 - 19 17 289 3 51 867 20 - 24 22 484 5 110 2420 25 - 29 27 729 11 297 8019 30 - 34 32 1024 22 704 22528 35 -39 37 1369 34 1258 46546 40 - 44 42 1764 42 1764 74088 45 - 49 47 2209 34 1598 75106 50 - 54 52 2704 20 1040 54080 55 - 59 57 3249 11 627 35739 60 - 64 62 3844 18 1116 69192 65 - 69 67 4489 12 804 53868 70 - 74 72 5184 9 648 46656 75 - 79 77 5929 8 616 47432 80 - 84 82 6724 2 164 13448 85 - 89 87 7569 2 174 15138 90 - 94 92 8464 2 184 16928 ∑n = 240 ∑= 11215 ∑= 582775
Faculty:
Faculty of Civil and Environmental Engineering
From this spot speed study, we are known for traffic operation establishing speed limits, determining safe speed at approaches to intersections. The road along Batu Pahat - Kluang highway was very dangerous and must take action to avoid the accident. Looks on the finding, Mean speed, maximum speed and minimum speed of each class is determined by using form SS2. The speed limit of this two lane highway is 60km/hr. Each of the mean speed of class vehicles gives the different speed. Which the class 1 is 63 km/hr, class 2 is 74 km/hr, class 3 is 60 km/hr and class 4 is 60 km/hr. The higher mean speed is at class 2 and the lower mean speed is class 3 & 4.
Based on the mean speed for class 2 that we found, it seems the speed is over the speed limit. There are cause by a few factor that can be influence such as, the road itself give the access for drive fast. Since the lane is straight then there are less of traffic lights there and the warning sign, so there is nothing to slow down the speed. Furthermore, the way of pavement there is still in good condition without any distress or deformation so there are no problem will be occurred when drive in fast. For the lower mean speed is class 3 & 4 because there are always must be take care of small vehicle like motorcycle. Like what we known, they are main factor for accident occur at there. Since that, the driver of heavy vehicles always is alert by driving carefully then slow down their vehicle speed. Base on analysis we found that the standard deviation of this road according our observation we got 16.74 km/hr, estimate standard deviation is 14 km/hr and the pace were in range 59 km/hr and 69 km/hr. The 85th percentile speed as obtained from the cumulative frequency distribution curve shown is 74.5 km/hr. It means that is a good guideline for the appropriate speed limit for that road and it indicates that the speed most of the motorists on the road to considered safe and reasonable under ideal condition. So, we must follow the suggestion that was told in comment part.
Department :
Department of Geotechnical and Transportation Engineering Title:
SPOT SPEED STUDY
Faculty:
Faculty of Civil and Environmental Engineering Department :
8.0 CONCLUSION
The objectives of this survey are to determine the speed characteristics of traffic at the location and to justify the problem of speeding at the location. From this experiment, we can be concluded that speeding is a problem at this location and may have contributed to road accidents which have occurred at this location.
This is supported by the results of the finding which show that mean, median, pace and 85th percentile speeds have all exceeded the 60 km/hr speed limit. In addition, about 27.5% of the drivers drive at speed between 59 km/hr to 69 km/hr and 85% of them drive at 74.5 km/h or below. All of this were above the maximum allowable speed and can be increased the number of an accident. In addition, 50% of the driver we detected to have driven over the speed limit.
1. Traffic engineering and safety, BFC 2082 , Universiti Tun Hussein Onn Malaysia 2. Nicholars J. Garber; Lester A.Hoel; Traffic & Highway Engineering (3rd Edition),
University of Virginia, 1995.
3. Paul H.wright & Radnor J.Paquette; Higway Engineering (5th Edition), Georgia Institute of Technology, 1979.
4. Bent Tagesen; Highway Engineering & Traffic (1st Edition), Technical University of Denmark.
5. www.wikipedia.com
Faculty:
Department :
Department of Geotechnical and Transportation Engineering Title: