The Use of a Suitable Simulation Tool for Traffic Modelling

54th International Scientific Conference of Czech and Slovak Universities and Institutions Focused on Research and Teaching Methods Related to Internal Combustion Engines, Alternative Powertrains, and Transport September 6th–8th, 2023, Hustopeče, Czech Republic Brno University of Technology, Faculty of Mechanical Engineering, Institute of Automotive Engineering THE USE OF A SUITABLE SIMULATION TOOL FOR TRAFFIC MODELLING Pavel Maxera 1 , Marek Semela 2 , Robert Kledus 3 , Martin Bilík 4 , Albert Bradáč 5 Abstract This paper focusses on traffic modelling, which is very relevant to the field of transport planning. The usability of the AnyLogic simulation software is illustrated in the form of a case study at a selected intersection. It is a universal simulation tool that can be used in many research fields (for example, in transportation, logistics, traffic, pedestrian movement, etc.). Using multimethod simulation modelling enables the creation of a wide range of different models with varying levels of detail. The case study evaluated the current state of the intersection during rush hour using simulation. Subsequently, the intersection modifications were designed and simulated in the form of traffic light installation and reconstruction into a roundabout. The comparison of the results showed that both proposed modifications would contribute to improving the current state, that is, eliminating the congestion and strengthening the traffic flow. The best results were achieved with the roundabout variant. The analysis confirmed the suitability of using AnyLogic software to solve this type of problem. 1 Pavel Maxera, Institute of Forensic Engineering, Brno University of Technology, Purkyňova 464/118, 612 00 Brno, Czech Republic, E-mail: pavel.maxer[email protected] 2 Marek Semela, Institute of Forensic Engineering, Brno University of Technology, Purkyňova 464/118, 612 00 Brno, Czech Republic, E-mail: [email protected] 3 Robert Kledus, Institute of Forensic Engineering, Brno University of Technology, Purkyňova 464/118, 612 00 Brno, Czech Republic, E-mail: kled[email protected] 4 Martin Bilík, Institute of Forensic Engineering, Brno University of Technology, Purkyňova 464/118, 612 00 Brno, Czech Republic, E-mail: [email protected] 5 Albert Bradáč, Institute of Forensic Engineering, Brno University of Technology, Purkyňova 464/118, 612 00 Brno, Czech Republic, E-mail: albert.brad[email protected] 2 1 INTRODUCTION In view of the ever-increasing number of vehicles on the roads, there is a growing need for appropriate traffic planning to prevent congestion and ensure the flow of traffic. In many cases, it is necessary to make appropriate adjustments to the road network for this purpose. As these are costly investments, it is necessary to analyse the impact of the proposed changes on traffic flow before they are implemented. To find the optimal solution, it is ideal to use the simulation modelling to help make the right decisions before making changes in the real world. One of the tools that enables this simulation modelling is AnyLogic software. Using this software, it is possible, for example, to plan traffic, simulate various modifications on the traffic network, adjust the timing and sequencing of traffic lights, process throughput analysis, etc. The aim of this paper is to analyse traffic flow at a selected intersection using traffic modelling in AnyLogic software to demonstrate the suitability of using this simulation tool to solve these types of problems. Within the analysis, the current state will be simulated, intersection modifications will be proposed, and the suitability of these modifications for traffic flow will be assessed. 2 METHODS 2.1 Choice of location The case study was developed for the intersection of Černohorská, Řečkovická and Příjezdová Streets, located in the Brno-Ivanovice district near the shopping mall, see Figure 1. Černohorská Street is the main street at this intersection. Figure 1 Selected intersection. [1] This intersection was chosen mainly because traffic congestion often forms during rush hour, especially when coming from Řečkovická Street. It is also a relatively dangerous place. Since 2014 to 2022, nine vehicle traffic accidents have occurred at this location [2], see Figure 2. The drivers suffered both slight (8 cases) and serious (1 case) injuries in these accidents. The cause of their occurrence was in most cases the disregarding the Give way sign, in one case, the driver was not paying attention to driving. 3 Figure 2 Number of traffic accidents – cause and seriousness of injuries. [2] 2.2 Simulation tool Traffic modelling was performed in AnyLogic software. This software is a universal simulation tool that allows multimethod simulation modelling, namely discrete event simulation, agent-based simulation, and system dynamics, see Figure 3. Using these methods enables to create models with different focus and on a very wide scale of detail. The modelling methods can also be combined with each other. Combining them allows the creation of unique models with the required level of detail capturing the vast complexity of the modelled systems, which cannot be achieved without combining the individual methods. Figure 3 Methods in simulation modelling. [3] Traffic modelling is usually performed at a low to medium level of abstraction. Since traffic flow processes at an intersection can be described by a sequence of discrete events, it is appropriate to use a discrete event simulation approach for modelling. 1 1 2 2 1 11 2014 2015 2016 2017 2018 2019 2020 2021 2022 Number of traffic accidents - cause and seriousness of injuries Disregarding the Give way sign Driver's inattention to driving Serious injury Slight injury 4 The software can be used in a wide range of different fields, providing a unique set of industry-specific tools in the form of various libraries, such as the process modelling library, the fluid library, the rail library, the pedestrian library, the material handling library, and the road traffic library. For the purposes of this study, the road traffic library was used, which contains the tools required to build a fully functional intersection model. This library allows planning, design, and simulating traffic flows at a detailed level. It can be used, for example, for planning roads and motorways, including intersections, crossings, roundabouts, car parks, and bus stops, assessing road capacity and throughput, evaluating levels of congestion, or setting the ideal timing of traffic lights. AnyLogic simulation software has already been used for traffic modelling in many studies. Coman and Badea [4] dealt with the optimisation of vehicle traffic flow in the urban transport system. In the study, they used discrete event simulation to simulate traffic flows at 2 signal-controlled intersections. In the simulations, they tracked the time of the vehicles in the model and used an optimisation experiment to find ideal traffic light timing values. An optimisation experiment to find the ideal traffic light timing values of traffic lights at Tianjin intersections was also used in the studies by Liu and Song [5] and Sun et al. [6]. Liu and Song [5] dealt with the problem of optimisation of traffic flow in a congested area using a discrete event simulation approach. Sun et al. [6] compared Synchro and AnyLogic software, the results showed that AnyLogic software provides an ideal way to solve traffic congestion. Kazmi et al. [7] solved the congestion problem at the T-intersection in Millerjord using discrete event simulation. In their study, they proposed alternatives to intersection modifications (installation of basic traffic signals, installation of optimised traffic signals, and installation of a roundabout) that reduce the generation of traffic congestion. They used the time in the model as a parameter to compare the simulations of each alternative. Ruškić and Mirović [8] compared two simulation software (Trafficware Synchro/Simtraffic, and AnyLogic) to analyse the estimation of left-turn capacity at the unsignalized intersection. The results showed that the results of the AnyLogic simulations were very close to the actual measured values. Shamlitskiy et al. [9] analysed the effectiveness of traffic control algorithms at a complex intersection. Other studies in areas close to traffic modelling also show the use of AnyLogic software as a suitable simulation tool. For example, Noma-Osaghae et al. [10] designed and tested a simulation-based intelligent traffic system to predict traffic flow patterns. In their study, they compared two developed models (a decentralised model and a centralised model). The modelling of bus routes was the subject of studies by Dashdamirov [11] and Spek [12]. Dashdamirov [11] used AnyLogic software to improve the interaction of Baku routes at high-density bus stops by adjusting the arrival time. To avoid queueing and time loss in front of bus stops, a model was created to coordinate bus timetables of different lines and adjust the arrival time at the stop without changing the intervals. Spek [12] developed a mixed agent-based and discrete event simulation model for a high-frequency bus route in the Netherlands for the formulation of transport policy. Karaaslan et al. [13] solved the model of the risk of traffic accidents involving electric vehicles and pedestrians at an intersection using an agent-based simulation approach. In the developed model many parameters such as ambient sound level, vehicle sound level, and ambient illumination were considered. The results showed the correlation of these parameters with the level of traffic accident occurrences. 2.3 Traffic model development 2.3.1 Traffic model To analyse traffic flow at a selected intersection in the Brno-Ivanovice district and to evaluate suitable modifications of this intersection, a traffic model was created. First, the roads including the individual turning lanes were drawn on the base of the map, see Figure 4. Subsequently, a flow chart was developed to define the logic of the traffic model, see Figure 5. The flow chart of the traffic model is made up of different blocks. The carSource blocks serve as a source of different vehicles coming from different directions in the model. Each vehicle in the model 5 represents an agent that can have its own physical parameters, such as length, speed, and acceleration/deceleration. The model considers cars, as well as vans and trucks. The number of vehicles was established according to the arrival rate per hour. Subsequently, based on the defined probability, the driving through the intersection, i.e. in which direction the vehicle will go, is determined using the Select blocks. The movement of vehicles through the intersection is then accomplished using CarMoveTo blocks (denoted in the model as ToN, ToE, ToW, and ToS according to the direction of movement). Vehicles leave the model in the carDispose block. Furthermore, the flow chart contains blocks to measure the time in the model. Figure 4 Road network of the traffic model. Figure 5 Flow chart of the traffic model. 6 2.3.2 Input data and parameter settings Different parameter values were set for each vehicle type, namely initial and preferred speeds, maximum acceleration, and maximum deceleration. Additionally, the values of the vehicle arrival rate and turning probability parameters were determined. The arrival rate has been determined based on traffic volumes based on the National Transport Census in 2020 by Road and Motorway Directorate of the Czech Republic [14], namely for the rush hour. These are therefore the maximum values. All the values of the parameters considered are given in Table 1. Table 1 Input data and parameter settings Car Van Truck Vehicle settings Initial speed 50 km/h 50 km/h 50 km/h Preferred speed 50 km/h 50 km/h 50 km/h Max. acceleration 1.8 m/s2 1.5 m/s2 1.0 m/s2 Max. deceleration 4.2 m/s2 3.5 m/s2 3.0 m/s2 Direction from the south (Černohorská Street) Arrival rate per hour 762 51 20 Probability of turning north / east / west 0.6 / 0.3 / 0.1 Direction from the north (Černohorská Street) Arrival rate per hour 762 51 20 Probability of turning south / east / west 0.6 / 0.3 / 0.1 Direction from the east (Řečkovická Street) Arrival rate per hour 762 51 20 Probability of turning north / south / west 0.6 / 0.3 / 0.1 Direction from the west (Příjezdová Street) Arrival rate per hour 109 7 3 Probability of turning north / south / east 0.1 / 0.5 / 0.4 2.4 Solution variants In order to perform traffic modelling, the current state of the selected intersection will be simulated using the developed traffic model. Subsequently, variants of intersection modifications will be proposed. In variant I, the intersection will be supplemented with traffic lights. The timing of the traffic lights will be set to 30 seconds (red/green light) for the main road and 20 seconds (red/green light) for the side roads. The orange light will be on for 3 seconds in both cases. In variant II, the design of the intersection will change and a roundabout will be added. The logic of the traffic model (flow chart) and the values of the input parameters remain unchanged in these variants. By simulating the traffic flow in these variants and comparing the results with the results from the current state simulation, the suitability of these proposed intersection modifications will be assessed. The simulation run time for all variants will be 1 hour. The count of vehicles that passed through the road network and the mean travel time of vehicles (time in model) across the road network will be used as parameters to compare variants. 3 RESULTS The results of the simulation runs of the analysed variants are described below. Finally, these results are compared with each other. 7 3.1 Simulation of the current state A simulation of the current state showed the problems that actually occur at this intersection in rush hour. Large traffic congestion occurs on the side road of Řečkovická Street, especially due to vehicles turning left in the direction of Brno. There is also a slight delay on the main road Černohorská Street. Visualisation of the simulation run is shown in Figure 6. This is complemented by a density map that indicates the critical sections of the roads where congestion is generated. The 3D visualisation is shown in Figure 7. Figure 6 Visualisation of the simulation run with the traffic density map (current state). Figure 7 3D visualisation of the simulation run (current state). The summary results show that 1 497 vehicles passed through the modelled road section in 1 hour of simulation time. The average vehicle travel time (time in model) on the road network was 101.9 seconds. In a time of up to 105.6 seconds, 73% of the vehicles (1 097 vehicles) passed through the road section. Detailed simulation results, including the histogram of travel time values, are shown in Figure 8. 8 Figure 8 Simulation results (current state) – histogram with mean value and detailed results showing the travel time of all vehicles across the road network. 3.2 Simulation of variant I – intersection with traffic lights The simulation of variant I (with the addition of traffic lights) is shown in Figure 9. Figure 9 Visualisation of the simulation run with the traffic density map (variant I – traffic lights). According to the density map, the delay at the intersection is evenly distributed between the higher volume roads. Improvement is noticeable on the side road Řečkovická Street, where the congestion is no longer so big. On average, vehicles travelled through the traffic network (time in model) in 88.4 seconds. In a time of up to 107.2 seconds, 77 % of the vehicles (1 216 vehicles) passed through the road section. However, the travel time in this variant is partly influenced by the timing of the traffic 9 lights. In general, there was an improvement in the throughput of this intersection compared to the current state, as 1 588 vehicles passed through the road network in the simulation time of 1 hour. Detailed simulation results, including the histogram of travel time values, are shown in Figure 10. Figure 10 Simulation results (variant I – traffic lights) – histogram with mean value and detailed results showing the travel time of all vehicles across the road network. 3.3 Simulation of variant II – intersection with roundabout The simulation of variant II (modification of the intersection into a roundabout) is shown in Figure 11. Figure 11 Visualization of simulation run with traffic density map (variant II – roundabout). According to the simulation results, modifying the intersection to a roundabout will provide higher throughput at this intersection. The delay at the intersection is evenly distributed between the higher volume roads. Furthermore, in this variant, there was an improvement in the throughput of this intersection compared to the current state, as 1 729 vehicles passed through the road network in the