Improving the Capacity of the Carriageway of the City Streets of Karbala

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Congestion on the roads in cities is one of the biggest transportation issues. Traffic congestion is a very intrusive activity for people and is brought on by high degrees of saturation of traffic flow. Due to the longer journey duration, congestion will have a detrimental effect on the driver or other road users. A population with a wide range of activities would have resulted in a mobility flow that needed suitable roadways to match [1; 2]. Jalan Raya Mandala, a major thoroughfare in metropolitan areas, frequently experiences satu- ration traffic flow at one specific location due to some form of pull traffic. Shopping centers are one type of high-traffic attraction. This is because the effectiveness of roads is significantly impacted by the impact of roadside barriers. Parking activity that uses the road is one type of side barrier that is frequently seen in the shopping district (on street parking). The width of the roadways utilized for park activities would result in a reduction in the capacity of the roads to handle the flow of passing cars, or, to use another phrase, a reduction in the capacity of roadways [3; 4]. HCM has provided comprehensive instructions for estimating Based on speed and other factors, capacity, and level of service. Adjustment factors for evaluating the capacity for various parameters are provided if the HCM handbook does not include side friction parameters for determining capacity and level of service [5]. Munawar made a comparison between the numbers reported by IHCM (1997) and the values found in the field data collected in Indonesia. He concluded that, as suggested by IHCM, there had been a considerable shift at high side friction values in the capacity trend (1997) [6]. Chiguma conducted a thorough investigation to determine the side friction’s impact on urban arterials in Dar-es-Salaam, Indonesia. The research examined how side friction affected section capacity and mean speed. The weighing variables of the side friction parts were quantified through the use of multiple linear regression analysis [7]. Using Indonesian Highway Capacity Guidance, or IHCG 2014[16], the level of service for DI Panjaitan Street was evaluated, and the most important component impacting side friction was found using multiple linear regression analysis in SPSS. The study found that levels from C to D were experienced from Tuesday through Friday, while levels of F were experienced on Mondays from 7 AM to 9 AM and between 5 PM and 7 PM Equation (1) was used to determine the side friction’s most important variable. SF= 0.157+ 0.002 1 + 0.001 X X 2 + 0.002 X3. (1) The study demonstrates that a non-motorized vehicle park’s stops, enters, and exits substantially match the degree of saturation with a correlation value (R) of 0.792 [8]. The goal of the study is to understand the various effects of side friction on the capacity of Yosodipuro Street, level of service (LOS), and saturation level. The Indonesian Highway Capacity Manual (IHCM) 19932 is the basis for the analysis. The survey was conducted over the course of one day, primarily between 6 A.M. and 12 P.M., along three different sections of Yosodipuro Street, each of which is 200 meters long. Geometric, data on side friction and traffic counting were collected from the field. According to the data, Yosodipuro Street has a maximum hourly volume of 2058.83 pcu/hour. This cir- cumstance occurs in Location 1 around 6:30-7:30, and this roadway can accommodate 2118.32 pcu each hour. Location 1, Location 2, and Location 3 each have a degree of saturation (DS) of 0.972, 0.638, and 0.632, respectively Each location’s LOS is: Locations 1 and 3 are D-Level, and Locations 2 and 3 are C-Level, according to the degree of saturation (DS). This indicates that while Locations 2 and 3 are in good shape, Location 1 is getting close to capacity [9]. The total capacity and the LOS of the roadway are impacted by the impedance that various types of HVs create for other vehicles in mixed traffic [10]. The most crucial factor in traffic control is on-street parking management so that the degree of saturation of traffic can be reduced. Road speeds and levels of saturation determine the service level [11][17]. The goal of the research was to evaluate how on-street parking is currently functioning. The analysis’s findings showed that both locations’ peak parking hours were in the late afternoon, notably after 4:00 PM, and that this was because of the concentration of activity at that time. The findings also revealed that, for both roads, most of the parked cars (80 percent) had wait periods of more than 30 minutes. They also stressed the fact that there was a lot of unlawful parking along the two streets they had inspected, both on the weekends and throughout the workweek [12]. Based on a combination of data and Green- shield’s theory, the capacity value of arterials showed a 9 percent decrease in value when considering side friction and established that pedestrian activity, which is one of the events that cause side friction, has the greatest impact on the traffic stream’s average speed across all study sections. Side friction levels ranged from very low to very high. 34 km/h was recorded as the average speed at low levels of side friction, and 19 km/h was recorded at higher levels. Therefore, the reduction was estimated at 51%, which is a significant amount [13]. The impact of side friction on an urban street’s capacity that is not divided. Side friction is a composite variable that describes how much regular traffic flow interacts with other nearby activities. Side friction significantly reduces capacity, with reductions ranging from 11.05 to 60.73 percent [14]. In general, it can be said that the presence of different side friction elements along the sides of urban roads causes a decrease in capacity and speed. on-street parking, Bus stops, and pedestrians, vehicles’ average speed significantly decreased by 21 percent, 27 percent, and 15 percent, respectively [15]. Founded effect of side friction on capacity, flow density, and free-flow speed in urban streets of Baghdad [16] On-street parking and non-motorized vehicles’ effects on an urban road’s performance as a side friction parameter on capacity have been implemented to overcome the randomness observed in capacity values [17]. average decrease due to roadside friction Stream speed can be observed in all study sections because of side friction. Bus stops and bus bays caused a stream speed reduction of 49-57%. While onstreet parking decreased stream speed by 45-67%. Due to transient bottlenecks resulting from onstreet parking, buses exiting and entering bus bays, and buses at the kerbside bus stop, roadside friction also reduced capacity. When using both kinds of PCUs, bus bays and bus stops reduce capacity by 10 to 53%. On-street parking reduced urban roads’ capacity by 28-63%, which had an adverse effect on their usability [18]. Urban multilane highways’ capacity and LOS for heterogeneous traffic may be evaluated based on a study of the segment capacity and level of service. The LOS’s of most of the segments are between C and D, and the segments’ base capacities range from 1850 to 1900 pc/h/ln [19]. The presence of side friction impairs the overall performance of traffic parameters. Roadway capacity and traffic speed can be increased by making some adjust- ments. Heterogeneous traffic, which includes slowmoving vehicles and non-motorized vehicles, reduces the effective road width as a result of vehicle parking along the side of the road, among other parking and unparking operations. These events are typically seen at a nearby market or commercial area. The side frictional parameter has already been taken into account by IHCM when calculating speed and capacity. Generally, in Indian urban cities, there are heterogeneous traffic conditions [20]. The increase in side friction in many urban streets led to an decrease in the speed in road networks, The aims of this study to know the influence of side friction on speed by using the Indonesian Highway Capacity Manual (IHCM 1995)[18]. This study uses the Indonesian Highway Capacity Manual (IHCM 1995) to calculate the side friction levels to determine the level of side friction. In this study, side friction data during peak hours between 7:30 and 9:30 in the morning and between 4 and 6 in the evening. Numerous actions on the road were recorded using the videography technique. Roadside activities were observed over a 200-meter section to determine the direction of the traffic under consideration. By observing the frequency of various activities, such as traffic flow rate, pedestrian movement, and parking, U-Turn movement and Entire-Exit operations. The SF data and traffic flow are extracted from the video film at 5-minute intervals. Results of a traffic survey and a side friction survey were processed using IHCM 1995 [22]. For measurement of side friction, procedure followed by Pal and Roy is used in present study [21]. This method uses the pedestrian influencing area as standard parameter to calculate equivalent pedestrian units for the events other than pedestrian. The stopped vehicles are converted into equivalent number of pedestrian units for standardizing the static side friction activity. The frequency of all stopped vehicles was converted and added with frequency of pedestrians observed in the field. The equation (2) is used to estimate the Pedestrian equivalency unit (PEU) for converting all stopped vehicles into equivalent number of pedestrians. The PEU is multiplied with the frequency of events to convert the vehicles into pedestrian units. Projected area of pedestrians, vehicle type and PEU is shown in Table 1. PEUi = (2) PEUi =14.53 , (3) where, PEUi is the pedestrian equivalency unit of the subject vehicle, PAi is the projected area of the subject vehicle and PAp is the projected area of the pedestrian. The number of pedestrian events and stopped vehicles are added to calculate total static side friction frequency in terms of PSPU (events/hr) which is estimated by using the equation (4). NPSPU =N p + (PEUi Ni ), (4) where, NP is the frequency of pedestrians, PEUi is the pedestrian equivalency unit of the subject vehicle and Ni is the frequency of the subject vehicle. Entry-exit vehicular movement and wrong movement of vehicles those are moving activities that contribute to side friction on the road. Side friction (SF) was calculated by estimating weighing factors of the events observed on the roadside. To estimate the weighing factor for each roadside activity, L. Chiguma [7] estimated the standardised coefficients and weighing factors using regression method by taking average stream speed as a per- formance measure variable. Similar methodology is adopted in the present study to find the relative weights of roadside activities. By taking stream speed as a performance measure, the relative weighting factors of each activity was estimated for determining SF (Events/hr) on the selected road sections. The SF (Events/hr) for each section was calculated by using the equation (5). SF is the side friction which is the sum product of roadside events frequency of different activities and their estimated weighing factors [7]. SF =(RW N1 PSPU )+(RW N2 EE )+ +(RW3 NWM ), (5) where, NPSPU is the frequency of pedestrians and parked vehicles in equivalent pedestrian units, NEE is the frequency of entry-exit vehicles, NWM is the frequency of wrong movement vehicles and RW is the relative weights of each activity type. Table 1 shows the frequency distribution of the side friction data for the second segment. It is noted that pedestrian activity increases signifi- cantly compared to the activity of parked vehicles. The highest value for pedestrian crossing is reached 504 (Event/hr), while parked vehicles are 276 (Event/hr), the U-Turn movement vehicle element’s frequency peaked at 600 (Event/hr) and the Enter-Exit vehicle element’s frequency peaked at 540 (Event/hr). We observed that the side friction components in this street do not have a zero value. Figure 2 showed how often the side friction elements occur on Al-Iskan Street at its peak period. In the figure, it can be observed that the parked vehicle values for this segment are gradually rising as their values range between (60-252 (Event/hr)), whereas the pedestrian cross- ing element’s values are repeatedly high asthey range between (96-492 (Event/hr)), the U-Turn movement element’s values are repeatedly high as they range between (492-840 (Event/hr)) and the Enter-Exit element’s values are repeatedly high as they range between (256-486 (Event/hr)). Figure 3 Often showed the side friction elements occur on Ramadan Street at its peak period. In the figure, it can be observed that the parked vehicle values for this segment are gradually rising as their values range between (0-216 (Event/hr)), whereas the pedestrian crossing element’s values are repeatedly high as they range between (84-408 (Event/hr)), the U-Turn move- ment element’s values are repeatedly high as they range between (840-1080 (Event/hr)) and the Enter-Exit element’s values are repeatedly high as they range between (624-792 (Event/hr)). Figures 4-6 show that there is a clear difference in the values of the side friction elements for both segments of Al-Tarbia street during the morning and evening. During the morning period, the side friction values begin to increase and gradually decrease during the evening until they reach the lowest values. The highest value of the pedestrian crossing component of the first segment during the morning period was 1140 (Event/hr) at the period between 9:15 am to 9:20 am, is higher than the vehicle parking component, which had the highest value of 348 (Event/hr) at the period between 8:55 am to 9:00 am. During the evening period, the highest value of pedestrian crossing reached 912 (Event/hr) The highest value of parked vehicles reached 324 (Event/hr) at the period between 12:45 pm to 12:50 pm. Figures 7, 8 show the recurring distribution during the morning and evening period for the first segment of Al-Abbas Street, where it was observed an increase in the parked vehicles component at the morning period. Its value ranges between 0-300 (Event/hr) and decreases in the vehicles ranges between 120-204 (Event/hr). Through the figures, it can mention that the value of the pedestrian crossing element is higher than the element of parked vehicles, as it reaches the highest value during the morning 804 (Event/hr) and the evening 372 (Event/hr). The IHCM has defined side friction levels as High and Low Levels since 1993. The IHCM lays out the roadside friction aspects that must be considered when calculating flow and capacity. The side friction was divided into four categories based on the fluctuation in the speed data in Table 2. Tables 3-5 shows the effect of SF on all streets selected during the morning and evening periods was very high, which affected the capacity Indonesian Highway Capacity Manual (1997)Directorate General of Highways, . of the street and reduced the speed by about 51%. Republic Indonesia, Jakarta and government departments, therefore, it requires 1. All the side friction values were very high traffic engineering solutions. for urban streets during the evening and morning 2. The highest value of SF was 4976 (Event/hr) peak periods as a result of the presence of schools during the morning period of Al-Tarbia Street. 3. The highest value of SF was 4792 (Event/hr) during the evening period of alsoAl-Tarbia Street. 4. The study found that the percentage reduction in average speed is 51% because of the side friction was very high on all urban streets.

About the authors

Hayder S. Khudhair

RUDN University

Email: hyder.s@uokerbala.edu.iq
ORCID iD: 0000-0002-6833-7780

Postgraduate student of the Department of Engineering and Transport Technologies, Academy of Engineering

Moscow, Russia

Hamid A.E. Al-Jameel

University of Kufa

Email: hamid.aljameel@uokufa.edu.iq
ORCID iD: 0000-0002-1367-4421

Doctor of Technical Sciences, Professor of the Department of Civil Engineering, Faculty of Engineering

Kufa, Iraq

Vladimir N. Konoplev

RUDN University

Author for correspondence.
Email: konoplev-vn@rudn.ru
ORCID iD: 0000-0003-1662-6254
SPIN-code: 3876-1534

Doctor of Technical Sciences, Professor of the Department of Engineering and Transport Technologies, Academy of Engineering

Moscow, Russia

Artur R. Asoyan

RUDN University

Email: asoyan-ar@rudn.ru
ORCID iD: 0000-0002-1976-9376
SPIN-code: 1020-5089

Doctor of Technical Sciences, Professor of the Department of Transport, Academy of Engineering, RUDN University; Professor of the Department of Operation of Road Transport and Car Service, Moscow Automobile and Road Construction State Technical University

Moscow, Russia

References