In Egypt, speed humps are often thought as the best and cheapest tool to reduce vehicles speed and consequently decrease thenumber of potential accidents. +e lack of standards in Egypt led to the installation of a number of speed humps with randomdimensions and without good justification.+ey have become inmany cases a source of disturbance and discomfort to drivers andpassengers especially when they are poorly designed and located. So, standard design guidelines are disparately required. +reestreets from the urban road network of Kafr El-Sheikh city were chosen to collect field data. A total of 51 speed humps were chosenfor field data survey. Although there are many design shapes of speed humps, the study focused only on the sinusoidal type. Asobserved in the field survey, it was found that more than 74% of the observed road humps were of the sinusoidal type. +escreening process resulted in only 24 sinusoidal shape speed humps from the 51 speed humps firstly chosen. For speedmeasurement, data were collected by installing a recording camera beside the road carriageway of each speed hump for an hourtime interval. Spot speed for three types of vehicles was measured from the recorded videos for each site by using the loggerprogram software. +e operating speeds (V85%) at humps locations have been obtained for different vehicles. Regression analysismodels were developed to represent the relationships between the operating speeds (V85%) at humps locations for motorcycles,passenger cars vehicles, and microbuses and three variables, hump length, hump height, and the spacing between successive speedhumps. Generally, the results demonstrated that spot speed is significantly influenced by speed hump geometric dimension andthe spacing between them. Finally, the developed regression lines can be used easily for setting the geometric dimensions for eachproposed hump location.
1. Introduction
Traffic calming is defined by the Institute of Traffic Engineers(ITE) as “the combination of mainly physical measures toreduce the negative effects of motor vehicle use, alter driverbehavior, and improve conditions for nonmotorized streetusers” [1, 2]. Since speed humps are a very effective means ofcalming traffic, themain purpose of installation of speed humpsis to reduce speed and volume of traffic to acceptable limits inorder to enhance safety for pedestrians and motorists [3].
+ere are many traffic calming devices that could benoticed overall Egyptian roads. +ese are speed humps,
speed bumps, speed tables, roundabouts, transverse rumblestrips, optical speed bars, textured pavement, and cat-eyereflectors but the speed humps are considered the most usedmeans of traffic calming in Egypt [2, 3].
In order to fight against speeding, the government andpeople opted for the construction of speed humps. As aresult, the speed humps spread along most Egyptian roads,and they have become a source of disturbance to all roadusers. Also, they may result in considerable traffic jams; thisis due to the random way in which humps are installed.
Speed humps can have different heights, base widths,and shapes. In fact, no particular design is suitable for all the
HindawiAdvances in Civil EngineeringVolume 2018, Article ID 3093594, 12 pageshttps://doi.org/10.1155/2018/3093594
types of vehicles using the road. Despite the widespread ofspeed humps in most Egyptian roads, standard designguidelines are not readily available. Consequently, there is anurgent need to investigate the effect of speed hump char-acteristics on vehicle speed, in order to determine the ap-propriate dimensions of different humps according to theirpurpose.
So, the main purpose of this paper is as follows:
(i) Conducting a field study to examine the impact ofspeed hump characteristics on hump-crossing speedfor different vehicles types
(ii) Obtaining a statistical model to examine the impactof speed hump characteristics (length, height anddistance between consecutive humps) on hump-crossing vehicle speed for different vehicles types
(iii) Developing the best models in graphical forms thatcan be a useful tool for highway and traffic prac-titioners to design hump geometric dimension fordifferent speed control limits for different types ofroads and vehicles
Finally, this paper presents the field data that have beencollected and analyzed in order to evaluate the effect of speedhump characteristics on hump-crossing vehicle speed.Video recording data collection method was employed foran hour in each speed hump location in the chosen studyarea. +e approaching vehicles spot speeds at humps’ lo-cations were then obtained from the video recordings foreach site by using the logger program software. +e dataobtained for a number of urban roads in Kafr El-Sheikh citywere then analyzed in order to develop the best model thatcan be generalized as a typical model in Egyptian cities.
2. Background
High traffic speed on local roadways led to an increase inunsafe roadway conditions for pedestrians and bicyclists. Asa result, governments all over the world have focused onefforts on improving the safety of local communities to facethese consequences [4]. Using measures to “calm” the trafficis one of the means to help governments do this effectively.
+e most important objective of the traffic calmingtechniques is the reduction of speed o vehicles. +is can beachieved using many different methods that involve mod-ification of either the road layout or the drivers’ behavior [5].+e traffic-calming techniques can be classified as given in[6]:
(1) Police enforcement(2) Visual stimuli (traffic signs and signals)(3) Tactile stimuli (devices that produce distinct noise
and vibrations inside the passing vehicle)
Tactile stimuli include the vertical raising of the roadpavement with the use of different devices such as “humps”and “bumps” which are currently installed in many coun-tries. It should be mentioned that the most noticeable dif-ference between speed hump and speed bump is that thelength of the speed bump is shorter than that of speed hump
for approximately the same height [7]. +is short length ofspeed bump can seriously damage the passing vehicles aswell as could lead to the loss of vehicle control if it is passedat unsafe high speed.
To give full description of a speed hump, several pa-rameters are used. +ese parameters include geometric andlayout design parameters. +e geometric parameters includehump length, hump height, hump profile, and hump widthas shown in Figure 1. +e layout parameters include spacingbetween speed hump, construction materials, marking, andsignage.
A speed hump is a raised area from the pavement, in-stalled transversely to the traffic flow and having severaldesign shapes such as sinusoidal, circular, parabolic, andflat-topped profile [3]. +e speed humps are supposed toserve two main objectives, the first is to force the drivers todecrease their speeds to avoid the uncomfortable crossing onthe hump and the second is to reduce the rate of accidents[2]. +e speed humps can reduce the speed of vehicles gentlyto 15 km/h to 30 km/h, and they may cover the entire widthof the road or cover a part of it [7].
Length is the most important speed hump geometricdesign parameter where effective humps should be at leastas long as a vehicle wheelbase to isolate the effects ofentering and exiting the humps for these vehicles [8]. Speedhump heights can influence the magnitudes of verticalaccelerations and the maximum levels of perceived dis-comfort [9].
+ere are many design shapes of speed humps. +eoldest design shape is the Watts profile or circular speedhump. It is s section of a 3.7-meter-long cylinder with aheight of 75 to 100mm extending over the whole width ofthe road [10]. Accordingly, another design developed in theUnited States is the Seminole profile or “flat top” hump. +edesign is characterized by the addition of a 3-meter flatsection into the Watts profile hump with a total length of6.7m [10]. Figure 2 shows Watts and Seminole profile speedhumps.
2.1. &e Impact of Speed Humps’ Characteristics on Vehicles’Speed. It is worth mentioning that very little work has beendone to study the effect of speed humps’ geometric char-acteristics on vehicles speed in Egypt since there is notnationally accepted standard or design guidelines for speedhumps dimensions have been approved. On the contrary,past studies in a number of countries showed a decrease inthe 85th and 50th percentile of speed at hump location[7, 11–17]. +e operating speed (85th percentile speed) isdefined as the speed at or below which 85% of all vehicles arespotted to travel under free-flowing conditions at a specificpoint [7].
+ere are also a number of studies that have examinedthe effect of changing the characteristics of the speed humpon vehicle speed [7, 17–19].
+e effect of changing the hump height on speed re-duction was studied by Antic et al. using different heights(3 cm, 5 cm, and 7 cm) with a constant hump length [18]. Acomparison and an analysis of these speed measurements
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using ANOVA and post hoc are given in the study. Medianspeed (V50th) percentile and operating speed (V85%) per-centile were compared to each other before and after speedbumps installation. Finally, as normally expected, it wasfound that the vehicle speeds reduced as hump height in-creased [18].
In the same context, a study was conducted by Yaacoband Hamsa in Taman Setapak, Kuala Lumpur, showed thatthe speed variations were larger in a hump of 60mm heightas compared to another hump of 80mm height [19]. �egentler slope of the 60mm hump resulted in more vehiclesexceeding the speed limit 30m before and after the roadhump location [19].
Notably, there are not many studies that have beenconducted to link the hump-crossing speed and di�erentcombinations of geometric design parameters of roadhumps, which include hump length, hump height, and thedistance between consecutive humps.
According to the �eld study carried out by Sahoo inBhubaneswar, India, on geometric characteristics of speedhumps and hump-crossing speeds of two wheelers andpassenger cars vehicles [17], the hump-crossing speed waspredicted based on the area-to-width ratio of all 30 sitesusing di�erent geometric designs of the speed humps, whereR2 equaled 0.56 for two-wheeled vehicles and 0.60 forpassenger cars [17].
In Malaysia, �eld study was carried out by Zainuddinet al. to determine the relationship between the operatingspeed (V85%) reduction and the geometric design parametersof the hump [7]. A laser gunmeter was used to determine the
spot speeds at the speci�ed locations of the speed humps.�e results shown that a regression model could be de-veloped, and this model can be used as the basis for de-signing a speed hump geometry (hump length and height)according to the operating speed (V85%) at speed humplocation [7].
A study was conducted by Purnomo et al. in Surakarta,Indonesia, to analyze the correlation between speed bumpdimensions and the observed speed of vehicles at a distanceof 8 meters before the speed bumps [20]. �e independentvariables were the length and height of speed bumps andthe dependent variable was spot speed [20]. �e resultsshowed that the height of speed bumps is the most in-�uential factor to decrease speed in the area before thespeed bumps [20]. On the other hand, Sundo and Diazcarried out a study to prove the relationship between thespeed hump pro�le and the speeds at humps. �ere was asigni�cant variation of the observed entry speeds [21].�erefore, they pointed out that the height/length ratio wasnot a good explanatory variable to determine the entryspeeds and that driver’s behavior is also an important factorin determining vehicles speed [21].
In order to evaluate the speed pro�les of individualvehicles on tra�c-calmed streets in Christchurch, NewZealand, a study was conducted by Daniel et al. [22]. �estudy included speed data collection at 17 Residential Streetin Christchurch. �e Watts pro�le speed humps were100mm in height and ranged from 3.6m to 3.8m in length[22]. A ProLaser III light detection and ranging (LIDAR)meter was used to collect speed data. �e results showed
Width (W)
Width (W)
Width (W)
Height (H)
Height (H)
Height (H)
Length (L)
Length (L)
Length (L)
Circular
Sinusoidal
Trapezoidal
Figure 1: Geometric design parameters of speed hump [7].
75–100mm
75–100mm
6700mmSeminole profile hump
3700mmWatts profile hump
Figure 2: Watts and Seminole pro�le speed humps [10].
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that the speed humps provide the lowest operating speedand are also the most effective mean in reducing the speedof the streets. +e results also showed that at a spacing of170 or more between speed humps, it is expected that theoperating speed (V85%) will exceed 50 km/hr [22]. +estudy recommended that the spacing between bumpsshould be 85m or less if the desired speed is less than40 km/hr. [22].
Despite the effectiveness of speed humps in increasingtraffic safety, it may adversely affect the speed of emergencyvehicles [23, 24]. Some researchers have confirmed that theemergency response services are the toughest opponents tothe installation of speed humps [23, 23]. +e delay time thatoccurs depends on the type of emergency vehicle and thedesired operating speed. For instance, in the MontgomeryCounty, the hump-crossing speeds for a tiller style laddertruck, a pumper fire engine, an ambulance, and an aerialtower truck were 9.7, 14.5, 13.9, and 17.3 km/hr, respectively[24]. Consequently, the use of speed humps can cause anegative effect to emergency response times. If there no strictcontrol on its installation process according to well-considered standards, other means should be consideredfor calming traffic in residential areas [2].
Based on the above, speed reduction is the main ob-jective of using speed humps and thus increasing trafficsafety. A review of the various studies indicates that theeffectiveness of the speed hump depends on many factors,including geometric dimensions, speed hump shape, thespacing, the surrounding environment, and vehicle type.However, the information presented in previous studies isnot always compatible. For example, many studies did notshow the dimensions or number of speed humps, vehicletype, and the location of measurements. For this reason, it isdifficult to compare previous studies due to the lack ofconsistent information.
3. Data Collection Procedures
+e study was conducted in the city of Kafr El-Sheikh. It isthe capital of Kafr El-Sheikh Governorate, Egypt. +e city islocated in the Nile Delta of lower Egypt and about 134 kmnorth of Cairo. +e population of the city, according to thelast census in 2012 from the Central Agency for PublicMobilization and Statistics (CAPMAS), is 160,266 in-habitants. It is the fourth largest city in the Nile Delta area,and it hosts Kafr El-Sheikh University with its educational/research institutions and educational hospitals, which areconsidered a trip destination for many students/employees/patients. +e road directorate of Kafr El-Sheikh city adoptedsome of the measures to reduce speeds in some areas insideand outside the city in order to maintain the safety of roadusers. One of these measures used is speed hump in order toreduce the speed and hence reduce the number and severityof potential accidents.
+e data collection procedures involve field site survey.Data from the field site survey stage were screened to de-termine the suitable sites to conduct speed measurement asper the selection criteria given below. +en speed mea-surements were carried out using video shooting for an hour
in the vicinity of each hump site. Spot speeds were obtainedat each hump location using video recording technique. +elogger program software was used for the analysis of therecorded data.
3.1. Urban Road Selection Criteria. Urban road selectioncriteria were set as a guide to select a number of urban roadsin Kafr El-Sheikh city. Firstly, the selected residential areashould have existing speed humps cited at the collector/distributor or local streets. Secondly, the selected humplocation should have sufficient vehicle volume to allowadequate data collection for speed so that a minimum of 50samples can be obtained within an hour [25]. +irdly, theselected urban areas chosen for data collection should be acombination of both old and new residential areas; hence,such mixed land uses include different environment androad user behavior which would be a typical situation inmost Egyptian cities.
+erefore, three streets from the urban roads of Kafr El-Sheikh city were chosen to collect field data. Table 1 showsgeometric characteristics of the selected urban roads.
3.2. Field Survey. Two different types of data were measuredand identified for all humps on the specific roads. +e firsttype was the physical entity, which included the designshape, the geometric dimension of speed humps, the roadwidth and the distance between successive speed humps, andthe type of material the speed hump is made of. +e secondtype was the nearby signs and devices, which includedwarning sign and road marking.
A total of 51 speed humps were found on the selectedurban roads according to the criteria suggested earlier, andall the information were recorded based on the twocharacteristics mentioned above. Out of the 51 speedhumps, there were 13 speed humps with a circular profile,while the remaining 38 humps with a sinusoidal profile. Itshould be mentioned that all observed speed humps aremade of asphalt. Other speed humps made from othermaterials have been excluded this is because their numberis a few.
3.3. SpeedHumps SelectionCriteria. In this stage, data fromthe field survey stage were screened to determine theappropriate locations for speed measurements. Althoughthere are many design shapes of speed humps, the studywas centered only around the sinusoidal type. As observedin the field survey, it was found that more than 74% of theobserved road humps were of the sinusoidal type. It isworth mentioning that in this research, data were col-lected on permanent speed humps which are made ofmore rigid materials and are built as an integral part of theroad. +e common materials used in the construction ofspeed humps in Egypt are hot asphalt and cast concrete inplace.
Speed humps selection criteria were set as a guide toselect the suitable humps’ locations for speed measure-ments. Firstly, these humps should have been established
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by the road directorate of Kafr El-Sheikh city. Secondly, theselected hump area should not have any other means forspeed reduction except the presence of the hump. So, thehump location is rejected if it is near a signalized in-tersection or a sharp curve.+irdly, humps that have severedefects in the pavement surface are excluded as in this case,the effect of the dimensions of the speed hump is not onlythe reason for speed reduction. Fourthly, the selected speedhumps should be installed for more than 1 year to be sure ofthat the regular users of each hump were familiar with thehump dimension and able to cross the speed hump at theirselected speeds without disturbing the occupants of thevehicle [26].
Based on the above, 24 speed humps out of the 38 speedhumps that had a sinusoidal profile were selected. Figure 3shows the urban roads and the locations of selected the speedhumps.
3.4. Speed Measurements. +ere are several methods toobtain the spot speed of vehicles in a traffic stream and themost common methods are video analysis method, radarmeter method, and stopwatch method. By using the stop-watch method, the spot speed can be easily measured using asmall sample size observed during a relatively short distanceand a short period of time. It is an inexpensive and quickmethod for conducting a speed study.
A radar meter is another common method for directlymeasuring the spot speed. +e radar meter can be used inseveral modes, so it can be installed in a vehicle, installed ona tripod, or hand-held. It can be used for measuring speedswithin a distance ranging from 200 feet up to 2 miles [27].+is device needs only one person to operate it and alsoneeds a line of sight to accurate measurement for speeds.Two radar devices may be used if traffic condition is heavy.On the other hand, spot speed can be obtained from videoanalysis [28].
For spot speed measurements using a video recordingmethod, it is required to set up a video recording cameraon a tripod beside the hump location on the sidewalk. Twocalibration marks or a reference distance can be selectedon the screen for specific distance. After recording thevideo, it can be analyzed using some programs on thecomputer; one of these programs is called the loggerprogram.
+e logger program software is based on the fact that thespeed of an object is a measure of how far it moves in a settime period. +erefore, the first step in calculating the speedof an object on a screen is to calculate the distance the objectmoved. Once this is determined, it is required to know whatthe frame rate of the video recording is. +e frame rate,expressed as fps or frames per second, is the number offrames or images the camera can take per second [28]. +estandard specification for the camera used in the speedmeasurements in this paper is 30 fps; this means that there is1/30 second between any two successive frames. Based onthe above, the program can calculate the distance any objectmoves from one frame to the next and then calculate the spotspeed of that object.
Due to the limited resources available in the university,the researcher has chosen the video cameramethod to obtainthe vehicles’ speed in vicinity of the hump location. Inaddition, the logger program software version 3.14.1 wasutilized to calculate the vehicles’ speeds in the vicinity of thehump location.
Data were collected by installing camera as shown inFigure 4 for only an hour at the free-flowing condition iftraffic persists. Spot speed was calculated from the videorecorded for each site by using the logger program software.
It is necessary to know the reference distance betweentwo specific points, which is predetermined and marked onthe pavement before starting the video recording as shown inFigure 4. +is distance will be used later during the dataanalysis process in order to verify the speed measurementsobtained from the logger software.
Only speeds of the passenger cars, microbuses, andmotorcycles were collected for a minimum of an hour atevery site. +is is because the most prevailing vehicles’ typesfound on the study area were passenger cars, microbuses,and motorcycles.
All vehicles’ speeds were obtained near the humps’ lo-cations using the logger program software. +en using theExcel program, the operating speed at hump location hasbeen determined. Table 2 shows the dimensions of thehumps chosen for the study and the operational speeds ofvehicles (i.e., passenger cars, microbuses, and motorcycles).It should bementioned that motorcycle vehicle types includetwo and three wheels’ vehicles such as motorcycles, tricycle,and tok-tok.
3.5. Verification of Speed Given by Logger Program SoftwareVersion 3.14.1. To check the speeds given by the program, thevehicle speedometer was compared at different distances fromthe hump with the speeds given by the software. +is com-parison process was done using a number of vehicles and withthe help of the vehicle’s driver; the speedometer reading isrecorded at points previously identified on the road. At thesame time, a video is recorded for the same vehicle, and thespeed is obtained from the program at the specified points onthe road, and thus one can compare the speed obtained fromthe program and the speedometer at the same points. +eresults were verified five times, and the mean values weretaken as shown in Table 3. Figure 5 combines the program
Table 1: Characteristics of the selected urban roads.
Property Mubarakstreet
Abu Alaa AlMa’aristreet
El-masn’astreet
Length of theroad (m) 2400 1600 1150
No. of lanes/approach 2 2 2
Lane width (m) 4.15 5 3.5Median type Raised Raised RaisedMedian width (m) 4.2 4.2 4.8Speed limit(km/hr) 55 55 50
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interface and spot speeds of a vehicle at di�erent distancesfrom a hump. Veri�cation proved that the accuracy of theprogram results is greater than 90%, and this is consideredacceptable from the engineering viewpoint.
4. Results and Analysis
�is section discusses the correlation and regression sta-tistical analyses describing the relationships between thehump-crossing speed as a dependent variable and threevariables, namely, hump length, hump height, and thespacing between speed humps as independent variables. �estatistical package for the social sciences software (SPSSV22) program was used for conducting the statisticalanalysis of the obtained data.
4.1. Correlation Analysis. �is section is devoted to de-scribing the correlations between hump-crossing speeds andspeed hump characteristics that mentioned above. �iscould help for better understanding of the association be-tween hump-crossing speeds and variables representingspeed hump characteristics. Table 4 shows the correlationcoe�cients between hump-crossing speeds and speedhumps characteristics.
According to Table 4, the indicators of the correlationcoe�cients are as expected. For instance, the length of thespeed hump has a positive correlation with hump-crossingspeed. �is means that the hump-crossing speed trends toincrease as the length of the speed hump increases. While,the height of the speed hump showed a negative correlationwith hump-crossing speed, meaning that the higher theheight of speed hump, the lower the hump-crossing speed.Overall, the major observation is that the length and thespacing between speed humps have signi�cant correlationswith hump-crossing speed. On the contrary, it is clear thatthe height of speed hump has poor negative correlationswith hump-crossing speed.
4.2. Regression Analysis. Regression analysis was used torepresent the relationship between hump-crossing speedand three geometric variables (hump length, hump height,and the spacing between speed humps.). �e regressionanalysis produced many mathematical models of the in-dependent variables. �e criteria used to assess the pre-dictive accuracy of the models are as follows. Firstly, thehigher the coe�cient of determination (R2), the better themodel is to represent the data. So, the R-squared coe�cientmust be as high as possible and signi�cant at the 95%
Speed hump location
El-Masn’a street
Abu Alaa Al Ma’aristreet
Mubarak street
(17) (18) (19) (20)
(21) (22) (23) (24)
(6)
(7)
(8)
(13)
(14)
(15)
(1)
(2)
(3) (4)(5)
(12)(11)(10)(9)
Figure 3: Urban roads and locations of the selected speed humps.
Speed hump
Horizontal scope of the video camera
Reference distance
Digital camera
Road
wid
th
Figure 4: Installation of the digital camera at hump’s location.
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confidence level. Secondly, each of the independent variablesshould have regression coefficient that is significantly dif-ferent from zero.
A number of models have been developed for the re-lationship between the speed on the hump and the humpcharacteristics. Table 5 shows the best-fit models for pas-senger cars, microbuses, and motorcycles according toprevious criteria.
+e best models are models A3 for microbuses, B3 forpassenger cars, and C3 for motorcycles which can be writtenas the following equations:
V85%(microbuses)R2� 0.880 � 0.973 + 4.491L
− 14.88H + 0.010S,(1)
V85%(passenger cars)R2� 0.915 � 4.85 + 5.638L
− 59.0H + 0.012S,(2)
V85%(motorcycles)R2� 0.882 � 8.445 + 6.013L
− 76.866H + 0.017S,(3)
where the following can be noted:
(i) V85% is the speed below which 85% of all the vehiclesare driven in kilometers per hour, L is the length ofspeed hump in meter, H is the height of speed humpin meter, and S is the spacing between successivespeed humps
(ii) Equation (1) represents the predicted hump-crossingspeed of passenger cars based on three independentvariables, equation (2) represents the predictedhump-crossing speed of microbuses based on threeindependent variables, and equation (3) representspredicted hump-crossing speed of motorcycles basedon three independent variables
+e resulting coefficient of determination of the bestmodel for microbuses (R2) is 0.880, for passenger cars (R2)equal 0.915 and for motorcycles (R2) equal 0.882. It is foundto be significant at a 95% confidence level, as the significanceof the F statistic is less than 0.001.+e hypothesis that each ofthe coefficients is equal to zero can be rejected at the 95%confidence. +e t value shows the relative importance ofvariables in the model, as the greater the t value, the greaterthe contribution of the variables to the model. +e co-efficients of the independent variables are speed hump
Table 2: +e dimensions of the selected humps and operational speed.
Hump no. L H W S Microbus Passenger car MotorcycleV (85%)∗ V (85%)∗ V (85%)∗
(m) (m) (m) (m) (km/hr) (km/hr) (km/hr)1 2.00 0.10 10.10 150.10 8.70 10.88 12.202 3.25 0.08 14.00 310.00 19.58 24.84 28.443 2.70 0.12 14.00 110.00 12.252 15.62 21.524 2.70 0.10 12.00 180.50 13.32 15.48 21.215 2.70 0.11 14.00 220.00 17.52 19.21 23.116 4.90 0.10 15.00 360.10 26.64 33.12 38.257 1.70 0.10 11.00 190.10 7.54 8.33 11.528 1.70 0.11 13.00 220.20 8.25 9.21 13.529 3.20 0.10 12.00 210.00 16.25 19.52 23.2510 2.00 0.12 10.00 150.00 7.50 8.85 10.8911 2.40 0.10 12.00 210.00 12.66 14.42 16.8512 2.20 0.08 10.00 340.00 8.80 13.32 17.8813 1.70 0.08 12.00 300.25 9.55 11.98 16.5214 1.60 0.08 10.00 85.00 7.02 10.44 15.4815 1.60 0.10 12.00 270.00 9.36 11.16 17.7216 1.50 0.12 9.00 180.00 4.95 5.70 8.6217 1.40 0.10 8.00 140.00 8.95 9.42 11.5518 2.40 0.12 9.00 100.00 10.21 11.10 13.2119 2.20 0.10 9.00 185.00 11.52 12.54 15.5220 0.90 0.10 7.00 200.00 4.75 5.91 6.8021 0.60 0.10 8.00 190.00 5.40 5.90 7.1022 0.50 0.10 8.00 250.30 6.66 7.56 13.1423 0.50 0.12 7.00 90.00 4.51 5.22 6.5524 0.50 0.08 8.00 200.00 5.76 6.69 10.44V (85%)∗ is the operational speed in kilometers per hour; H is the height of speed hump, L is the length of speed hump, S is the spacing between theconsecutive speed humps, and W is the width of the road for each direction, all in meters for each approach.
Table 3: Verification of speed given by logger program software.Distance from hump (m) 0.00 10.00 20.00 25.00Speed from vehicle speedometer(km/hr) 19.00 36.00 43.00 45.00
Speed from logger pro. software(km/hr) 17.90 33.48 41.23 43.21
length, height, and spacing between humps. +e positivesign of the independent variables which include speed humplength and spacing between humps means that as the speedhump length and spacing between humps increase, hump-crossing speed also increases, as expected. However, thenegative sign of the independent variable speed hump heightmeans that as speed hump height increase, hump-crossingspeed will decrease.
Figures 6–8 show the observed values of hump-crossingspeeds (V85%) plotted against the predicted speeds. It isnoticeable that the observed values are closely correlatedwith those expected.+e figures emphasize the validity of themodels previously described.
4.3. Results Discussion and Sensitivity Analysis. +e bestmathematical models described previously can be
Table 4: Correlation coefficients between hump-crossing speeds and speed hump characteristics.
Vehicle type Height Length Spacing between humpsPassenger cars −0.208 0.931 0.535Microbuses −0.240 0.924 0.496Motorcycles −0.249 0.901 0.563
Figure 5: Program interface and the spot speed of the vehicle at different distances from a hump.
Table 5: Results of the best achieved model for speed hump characteristics on hump-crossing speed.
C3∗ Coefficient 8.445 6.013 −76.866 0.017 0.882 50.048 (0)t (p value) 1.383 9.760 −1.527 1.746Note. “t” means the t-test statistic; ∗the best model; H is the height of speed hump in meter, L is the length of speed hump in meter, and S is the spacingbetween two consecutive speed humps.
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represented in graphical forms. �ese graphs can be a usefuland fast tool for highway and tra�c practitioners to designhump geometric dimension for di�erent speed limits fordi�erent types of vehicles. Also, the potential operatingspeeds of di�erent speed humps can be compared for dif-ferent types of vehicles as well as the sensitivity analysis canbe conducted.
By using the MATLAB program version 9.1, a programwas created so that the equations obtained previously can beconverted into monograms. Figures 9–11 present the best-developed relationships. Depending on the tra�c compo-sition, the design vehicle can be selected and the appropriatemonogram will be selected. Accordingly, hump geometriccharacteristics can be chosen based on predicted hump-crossing speed and vice versa.
5. Conclusions and Recommendations
�e main objective of this study was to develop ideal humpgeometric characteristics for di�erent vehicles typescrossing speeds. �ree urban roads in Kafr El-Sheikh city(Egypt) have been chosen for data collection. Only 24 speedhumps installed on these roads were selected for crossingspeed measurements of di�erent vehicles’ types. �e col-lected data of geometric characteristics and spot speeds ofvehicles on these humps were analyzed from the recordedvideos on the sites using the logger program software. �emost important �ndings of this paper can be summarizedas follows:
(i) Based on the �eld study on humps characteristicsand hump-crossing speeds of passenger cars, mi-crobuses, and motorcycles vehicles, the results haveshown that statistically signi�cant regression re-lationships could be predicted.
(ii) A strong correlation was found between thehump-crossing speed and speed hump charac-teristics. �e height of speed hump showed anegative correlation with hump-crossing speed.On the other hand, a strong positive correlationwas found between length and hump-crossingspeed. In addition, a strong positive correlationbetween the distance between the successivehumps and vehicles speed.
(iii) Regression analysis was used to produce the bestrelationship between each hump-crossing speedand speed hump characteristics (length, height, andspacing between successive speed humps). �reemodels were developed for each vehicle typementioned earlier. �e resulted models showed asigni�cant prediction accuracy with R2 of 0.915 forpassenger cars, R2 of 0.880 for microbuses vehicles,and R2 of 0.882 for motorcycles.
(iv) �e developed models are presented in graphicalforms. �ese relationships can be a useful tool forthe highway and tra�c practitioners and �eld en-gineers to design hump elements for speci�c speed
0.0 0.2 0.4 0.6 0.8 1.0
1.0
0.8
0.6
0.4
0.2
0.0
Observed cumulative prob.
Expe
cted
cum
ulat
ive p
rob.
Figure 6: Predicted speed values against observed values formicrobuses.
0.0 0.2 0.4 0.6 0.8 1.0
1.0
0.8
0.6
0.4
0.2
0.0
Observed cumulative prob.
Expe
cted
cum
ulat
ive p
rob.
Figure 7: Predicted speed values against observed values forpassenger cars.
0.0 0.2 0.4 0.6 0.8 1.0
1.0
0.8
0.6
0.4
0.2
0.0
Observed cumulative prob.
Expe
cted
cum
ulat
ive p
rob.
Figure 8: Predicted speed values against observed values formotorcycles.
Advances in Civil Engineering 9
limit or estimating hump-crossing speed based onspeed hump characteristics.
(v) Based on the �ndings of this study, it is verynecessary for the roads directorates to put gener-alized standard and speci�cations when speedhumps are required. �e speci�cation should givegeometric hump characteristics (length, height,
shape, and spacing between humps) based on thedesired speed reduction. Developed models in thisstudy can be used to achieve this purpose.
(vi) �e speed humps are supposed to serve two mainobjectives: the �rst is to regulate the tra�c processand the second is to reduce the rate of accidents.Some other factors may need further studies such as
350
300
250
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150
100
50 5
10
15
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25
30
35
Spac
ing
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ps (m
)
Ope
ratin
g sp
eed
(km
/hr.)
H = 0.08H = 0.10
H = 0.12H = 0.14
Speed hump height (H) (m)
Speed hump length (L) (m)
L = 1 L = 1.5 L = 2 L = 2.5 L = 3 L = 3.5 L = 4 L = 4.5 L = 5
Figure 9: Predicted hump-crossing speed (V85%) based on hump characteristics for microbuses.
H = 0.08H = 0.10
H = 0.12H = 0.14
Speed hump height (H) (m)
50
100
150
200
250
300
350
Spac
ing
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hum
ps (m
)
5
10
15
20
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30
35
Ope
ratin
g sp
eed
(km
/hr.)
Speed hump length (L) (m)
L = 1 L = 1.5 L = 2 L = 2.5 L = 3
L = 5L = 4.5L = 4L = 3.5
Figure 10: Predicted hump-crossing speed (V85%) based on hump characteristics for passenger cars.
10 Advances in Civil Engineering
the effect of humps on pavement conditions, thebreakdown of vehicles, and the surroundingenvironment.
(vii) Most of the previous researchers have addressedthe effects of speed humps on vehicles speed andaccident rate based only on field data and simu-lations models. +e results of field studies can beanalyzed taking into account the public consul-tation and their opinion on the speed humps ef-fectiveness since the public opinion survey mayenhance the proposed speed humps geometriccharacteristics.
Data Availability
+e data used to support the findings of this study areavailable from the corresponding author upon request.
Conflicts of Interest
+e authors declare that they have no conflicts of interest.
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H = 0.08H = 0.10
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Advances in Civil Engineering 11
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