ENG5006 Technical Paper Using Virtual Reality (VR) to Reveal the Impact of Work Zone Disruptions Combined with Merging Sections on Driving Behaviour Richard Dong, Ruixin Huo, Yichao Xu, Liyuan Li, Zhuo Pan, Chen Xiao Discipline Coordinator: Nan Zheng,Zheng Xu ABSTRACT Existing roads require extensive maintenance and expansion work and, in addition to work zone, access ramps on the highway are also a considerable risk area for collisions. The optimisation of working areas close to ramps in accordance with driving behaviour is a necessary involved prospect. This study looks at the effects of the combination of the two on driver behaviour. An experimental simulation platform is built using a combination of virtual reality technology and artificially intelligent traffic flow to simulate the possible dangerous effects of driver driving behaviour in the absence and presence of traffic when the working zone is close to the on-ramp and off-ramp, as well as the more extreme case when the working zone completely closes the lane. Experiments are conducted to collect and analyse participant and subjective perception and objective driving data. The results show that longer braking distances do not guarantee safer driving behaviour when the work zone and the ramp are combined, that further restrictions on driver speed are needed and that collisions are more likely to occur when driving at too low a speed to leave the work zone and that blockages should be avoided. INTRODUCTION The effect of work zones on driving behaviour has garnered a wide interest with the increasing expansion of the freeway system to improve road infrastructure. The necessity to build develop the road infrastructure requires implementation of work zones, which can create disturbances such as lane closures that compromise the safety and operational efficiency of the road network. From 2 April 2019 to 30 June 2024, to accommodate Australia's growing population and the safety of the national transport system, the Australian Government has carried out the agreement of Land Transport Infrastructure Projects with $22,844.34 million funding (FFR, 2019). Road upgrading and construction projects are a common disruption on the freeway, and work zones are considered a contributing factor to traffic congestions and road accidents. In 2020, U.S.A. reported approximately 102,000 car crashes and 4,400 injuries in work zones. Approximately 10% of estimated national congestion is due to work zones (ARTBA, 2022). Consequently, the impact of work zones on driving behaviour during maintenance is therefore of great concern. Moreover, most of the hidden risks are associated with the merging sections of freeways, and they are considered to be the primary cause of bottlenecks and traffic conflicts (Xu et al., 2021). In addition, variations of traffic volumes and (lower) merging speeds of entering vehicles have been Page 1 of 22 ENG5006 Technical Paper recognised to have significant associations on the higher collision rate on acceleration lanes(Ahammed et al., 2008). On freeways, the major merging sections are the interchanges of ramp and main road of highway. In a sample of 1,150 crashes on ramps in Northern Virginia, approximately half of the crashes occurred while the driver at fault was leaving the interstate, 36% occurred while the driver was entering the interstate, and 16% occurred at the midpoint of the entrance road or on a ramp connecting two interstate highways (McCartt et al., 2004). Furthermore, Singh indicated that drivers were identified as the key cause in 94% of road accident reports, with driver identification errors accounting for 41% of crashes, decision errors accounting for 33% and performance errors accounting for 11% (Singh, 2015). This reflects the uncertainty of human driving behaviours as an extremely critical factor for road safety. In order to determine if any safety implications are related to the combination of freeway disruption and on-ramp/off-ramp, behavioural analysis must be conducted in order to determine how drivers perceive and react to the disruption. To investigate this further, this study examines work zones at the merging section of the freeway. Although there are extensive studies on the effect of mainstream disruptions or ramp merging section on traffic flow, only a few have investigated the behaviour of the individual driver. For example, previous studies have developed a time-varying mix logit model to reflect the vehicle merging behaviour in the work area during the implementation of the merging manoeuvre from the beginning to the completion of the merging manoeuvre (Ahammed et al., 2008). Based on the driver workload theory, the safety evaluation of the highway interchange merging area is carried out. The result showed that vehicles merging from ramps can affect driving performance by adding additional mental load whilst on the road. This generates a potential risk that cannot be ignored. Merging into the main traffic flow will increase the workload of drivers to a higher level and even exceed the safety threshold (Hu et al., 2020). Zhang et al. (2022) introduced a Nonhomogeneous Hidden Markov Model to decompose traffic merging processes into 3 primitives which include motivation to perform a lane-changing motivation, and then a process of the merging vehicle waiting for change lane, and the last one is completing the merging manoeuvre. As a result, the driving patterns during merging processes were identified and an evolutionary mechanism was revealed in congested traffic flows at onramps of freeways. In this study, the approach to this research is based on using microsimulation and virtual reality (VR), in combination with driving behaviour analysis. Virtual reality is an emerging reliable simulation technology that indicated similar results for 2D or 3D screens, and no significant differences were observed regarding physiological responses or behavioural patterns (Weidner et al., 2017). The results suggest that a significant number (40%) of the surveyed simulator studies may have been conducted via head-mounted displays. (Blissing and Bruzelius, 2018). Page 2 of 22 ENG5006 Technical Paper AIM In this project, the impact of different types of work zones on highways based on diverse scenarios will be collected and analysed. Driving data will be collected for analysis of driver’s behaviour, such as overall speed changes, collision frequency, acceleration changes, braking distances used to decelerate before reaching the work area, and driving trajectories. In order to make the result more generic, there are three basic work zones selected (Details would be described in Methodology part): • • • The work zone near to on-ramp (scenario 1) The work zone near to off-ramp (scenario 2) The work zone near to the road closure (scenario 3) Furthermore, since the environment of this project is VR, for realistic result, AI traffic flow is necessary during the simulated driving. The AI vehicle should have normal driving logic and be able to change lanes, shift gears, evade and cut in. METHODOLOGY The methodology for this research primarily resolves around three key stages, in which the first stage involves building a simulation of a freeway environment with different types of traffic flow and work zones on a VR platform; the second stage involves recruiting suitable participants to take part in the experiment to collect data; and the third stage evaluates the data to create a conclusion based on the correlation between different factors. Figure 1 illustrates the basic steps of this study. Figure 1 The basic steps of the research Page 3 of 22 ENG5006 Technical Paper Stage 1: Building the VR freeway environment on the simulation platform. The environment was based to the Citylink and Westgate Freeway which is the road network that links the Southbank and the Altona North in Melbourne. The type of junction is a Trumpet (tintersection of freeways) which is a simple conserve space way for freeway to normal way interchanges. Due to a high-speed carriageway ends in a low-speed loop, it is a most critical situation for the freeway road safety and capacity. The chosen ramp is a known blackspot where 51 crashes in total have occurred during the period 2014-2019; and 8.5 crashes occurred on average per year during the period 2014-2019. In particular, 20 fatal car accidents and serious injury car accidents occurred from 2014 to 2019, accounting for 39.2% of the total accident rate (Vicroad.vic.gov.au, 2021). According to the Australian "Guide to Temporary Traffic Management", there are several different work zone configurations, and they can result in different collision rates. The three workspace configuration types with the highest collision frequency are lane closure (39%), lane shift (22%) and crossover.(Gu et al., 2019) Considering the interaction of work zone and merging section in the freeway, this study will set up three major scenarios with different configurations laid on the different merging sections (see Figure 2, Figure 3.Figure 4), where the focus was on the combined impact of the work zone and ramp on the freeway merging behaviours. Microsimulation and virtual reality in combination with driving behaviour analysis was used, with highly accurate vehicle models with features and specifications based on actual vehicles to produce a simulation framework with naturalistic scenarios. Additionally, for the background traffic system, the AI traffic logic was handled by AI Traffic Controller and created waypoint-based routes that can be interconnected in a modular way in the scene. Moreover, to achieve the obstacle avoidance function, all background vehicles had virtual sensors attached, which allowed it to make changes accordingly when faced with construction-related lane closures. From the traffic volume data (Goverment, 2019), the data shows two-way average annual vehicles per day (AADT) is 200,000 veh/d, and trucks with 19,000 veh/d. The total number of average annual vehicles per day was set as 8300 veh/h. Heavy vehicles represented 9.5% of the total flow and was set at 791 veh/d. Likewise, the vehicles randomly spawn at a rate of 2 vehicles per second, from 600 spawn points, with a distance of 1 metre separating each point. Page 4 of 22 ENG5006 Technical Paper Figure 2 The 97 m long work zone that is next to an on-ramp encountered when a vehicle needs to travel from merging lane and merge onto freeway. Figure 3 The 97 m long work zone that that is next to an off-ramp encountered when vehicle needs to pull away from a merging lane and merge onto freeway. Figure 4 Vehicles leaving the freeway from the ramp next to the work zone when the freeway is closed In this study, a driving simulator (DS) was used for the experiment as driving simulation is an efficient, safe, and easy data collection method for examining driving behaviour in a controlled traffic environment. Previous research that involved using driving simulations include when (Lang et al., 2018) proposed a novel virtual reality-based driving training method in which participants drove along a route using a driving controller and an eye-tracking virtual reality headset, and traffic events on the road will help users improve their driving habits. And compared to VR-based driving training with other training methods, the results showed that participants using this training method performed better on average than those using other training methods in terms of assessment scores and response times, which indicating that VR driving Page 5 of 22 ENG5006 Technical Paper simulation has good working performance (Hussain et al., 2019). This study, based on the participants' speed perception observations, the speed perception and actual speed of the driving simulator were verified by experimentally recording their speed estimates, and then comparing actual speed observations from the actual field and the simulator. The results of these experiments show that the curves of the estimated and actual speeds have significantly similar trends, so that a stationary driving simulator can be a useful tool to study actual speed and speed perception, so the simulator is an effective tool for driving speed learning. The equipment was a Logitech G923 steering wheel and pedals, pressure-sensitive brake system, and proprietary TRUEFORCE feedback technology directly connect to in-game physics, as well as nonlinear brake pedals equipped with anti-slip system. The virtual reality device uses a head mounted Htc Vive Pro headset. The device has a built-in high-resolution AMOLED screen with a binocular resolution of 3K (2880 x 1600) and a field of view angle of 110 degrees. It uses two locators and supports spatial positioning tracking of 5m x 5m. The space is set according to the seat height of the test site. Stage 2: Acquiring participants and conducting the experiment A total of 26 people were recruited (14 males, 12 females) for the experiment, where all of them had varying degrees of driving experience. All participants were above 20 years old, hold valid driving licenses and have at least one years of driving experience. However, due to various external factors, 10 people were available to use the VR equipment and participated in the experiment. Each participant was allowed approximately 15 minutes to get used to the simulation as well as develop a “feel” for the control. The training scenario was a separate environment for participants to get a basic understanding of the layout of a typical road as well as the movement of simulated traffic flow. Once they reported adequate levels of comfort using the simulation device, each participant would then drive each of the scenarios two times. As a result, participants completed a total of 60 driving simulations. Questionnaire content Each participant filled out two questionnaires (APPENDIX D. Questionnaire (pre and post)) – a prequestionnaire prior to engaging with the VR equipment; and a post-questionnaire after completing the experiment. The pre-questionnaire was done to sort the participants into different categories to see if there was any correlation with the extent to which other factors influence driving behaviour when approaching work zones. Participants were also instructed that should they experience any symptoms such as nausea, dizziness, discomfort during the simulation, they should inform the researchers and the experiment would be concluded and the results discarded. The postquestionnaire aimed to indicate if there were any systematic variables that would be reasonably regarded to have influenced their behaviour. The post questionnaires used a 5 Point Likert Scale with “strongly disagree (1)”, “unsure (3)”, “strongly agree (5)”, and the types of data the questionnaire would collect is shown in the table below: Page 6 of 22 ENG5006 Technical Paper Table 1 Questionnaire Content Questionnaire Data type Pre-Questionnaire Demographic PostQuestionnaire Content Gender; age; driving experience (years); average hours driven per day (hours/day); average hours per week (hours/day) experience with VR Realism of VR If the simulation was reflective of real life, if there was simulation any difficulty controlling the vehicle Stage 3: Data collection and analysis The collection of data was an automated process that was coded into the simulation software in which the driving time, instantaneous vehicle position; and instantaneous vehicle velocity were recorded at 0.1 second intervals before being exported into Microsoft excel for data analysis to be conducted. Based on the data collected, analysis was performed to assess vehicle performance in which acceleration behaviour, vehicle trajectories, crash frequency, vehicle speed and braking distance, were plotted and investigated to see what sort of behaviour changes occurred based on the different types of work zone scenarios. Additionally, these trends were then compared to the feedback from the questionnaires to identify if there were other factors outside of the nature of work zones that would have caused any differences in behaviours. Page 7 of 22 ENG5006 Technical Paper RESULTS AND DISCUSSION Acceleration Behaviour Figure 5 The Cloud point distribution map of longitudinal and lateral acceleration As shown in Figure 5, the vehicle acceleration measured by the longitudinal and later acceleration in two-directions for all data collected. The longitudinal acceleration behaviours are intense at lower lateral acceleration ( ±2.5𝑚/𝑠 2 ) boundary with a 95% confidence interval, where the longitudinal acceleration is relatively gentle (± 5𝑚/𝑠 2 ) at the tail ends of the lateral acceleration (±10 𝑚/𝑠 2 ) with a confidence interval of 95%. Based on this observation, an increase in speed from an initial low velocity will lead to a high probability for variations to occur in longitudinal acceleration, and lower probability for variations in lateral acceleration. Conversely, higher vehicular speeds will have lower probabilities for variations in longitudinal acceleration and higher lateral acceleration behaviour when the vehicle speeds reduce over time. It is notable that the probability of longitudinal vs. lateral acceleration match in Pareto Distribution model. This is reflective in common traffic scenarios where road users tend to driver a lower speed under complex situations (created by workzones and merging induced by ramps), and faster under more simplistic environments. However, complex road environments also frequently have drivers performing rapid acceleration and emergency braking; something that is rarer to occur in more simple environments. Page 8 of 22 ENG5006 Technical Paper Vehicle trajectories The time-space diagram Figure 6, Figure 7 and Figure 8,shows the vehicle trajectories for different work zone configurations to indicate the locations in which the participants changed lanes. The slope of the line indicates the speed of the test vehicle, and the curved part of the line indicates that the speed of the test vehicle has changed. Figure 6 The trajectory of Scenario 1 Figure 6 above shows the trajectory of the work zone that is near to on-ramp. When there is a traffic flow in the work zone where is between 1150 m and 1350 m in the direction in which the vehicle travels, 9 out of 10 participants' test vehicles were able to smoothly perform the merging operation to the left lane, given that on the speed of the vehicles did not significantly change. However, 1 participant performed a sharp deceleration during the merge in the process of entering the work zone and collided with the vehicle in front. This can be seen by the purple line that has a horizontal inflection point at 1951 m, where the slope of this horizontal section is 0, showing that the instantaneous speed at that moment is 0 km/h, indicating an event that forced the vehicle to be stationary (in this case a crash). Compared with the condition of no traffic flow, the test vehicle can easily pass through the work zone at a steady speed when there is no traffic flow without any traffic accidents. For the lateral lane change trajectories, refer to APPENDIX A. Lane change trajectory of vehicle through Scenario 1. Page 9 of 22 ENG5006 Technical Paper Figure 7 The trajectory of the Scenario 2 Figure 7 shows the trajectory of the work zone that is near to off-ramp. When there is a traffic flow in the work zone where is between 530 m and 770 m in the direction of the vehicle travels, 8 participants' test vehicles successfully performed the merging operation to the left lane where the speed of the vehicles do not sharply change. Only 2 out of 10 test vehicles had to reduce speeds to merge and make a successful lane change, as shown on the green line and purple line. When there is no traffic flow, the test vehicles simply and steadily move through the work zone without any accidents, as opposed to when there is traffic flow. For the lateral lane change trajectories, please refer to APPENDIX B. Lane change trajectory of vehicle through Scenario 2. Page 10 of 22 ENG5006 Technical Paper Figure 8 The trajectory of the Scenario 3 Figure 8 shows the trajectory of the work zone that is near to the road closure. When there is a traffic flow in the work zone where is between 730 m and 770 m in the direction of travel, only 4 out of 10 participants' test vehicles could comfortably perform the merging operation to the offramp given that the speed of the vehicles had no rapid changes. 3 out of 10 participants' test vehicles were forced into the off-ramp by the configuration of work zone and performed a severe deceleration manoeuvre to avoid a crash before the test vehicles entered the off-ramp lane. It is worth noting that 3 out of 10 participants' test vehicles performed a significantly deceleration during the merge in the process of entering the off-ramp lane and collided with the vehicle in front. In contrast to when there is traffic flow, the test vehicle may go through the work zone slowly and methodically without any incidents. For the lateral lane change trajectories, please refer to APPENDIX C. Lane change trajectory of vehicle through Scenario 3. Crash Frequency The frequency of collisions was analysed for the three experimental conditions and a total of four collisions were observed. Three of these occurred in scenario 3 and one in scenario 1. In scenario 3, due to the full lane closure, all vehicles had to merge into the ramp, resulting in traffic congestion. During this scenario, there were reports of a visual difference between the virtual reality simulation and what was actually seen, resulting in the driver not being able to correctly judge the distance in front of the car and a collision occurred. Page 11 of 22 ENG5006 Technical Paper Figure 9 The observed collisions Figure 10 The position of collisions occurred In addition, all three collisions occurred after leaving the work zone insight of the very low speed of the congested vehicle contrasted with a tendency to accelerate. The crash at scenario 1 occurred just after entering the work zone, at a speed reduced to the speed limit requirement, due to avoiding a merging vehicle on the right. In previous studies, the risk of collision increases when drivers have low confidence in changing lanes, when merging vehicles are travelling at very high or very low speeds, and when merging vehicles approach the end of the acceleration lane and are forced to merge. The start of the acceleration lane is also an area of higher crash risk (Moradpour et al., 2015). The results in this study also support this result. Page 12 of 22 ENG5006 Technical Paper Vehicle Speed The mean operation speed of the 10 participants passing through different work zone scenarios for a 100km/h highway is shown in Figure 11. The average speeds of scenarios 1, 2, and 3 are 96.02±12.31, 82.89±9.7 and 40.6±21.1 km/h, respectively with p-value is 0.05. Comparisons between the driving speeds of the different participants to reveal the effect of work zones on vehicular speeds are done as described in the following: In order to remind the representativeness of vehicle speed for each of the participants when they engage in scenario 1, remove a minimum speed of 48km/h, and remove a maximum speed of 120km/h. Then the vehicle speed passing through scenario 1 work zone can be obtained as 80-120 km/h, so the average speed can be approximately considered as 96 km/h. Compared with the design speed 100 km/h of this highway, the passing vehicle speed of scenario 1 work zone is basically unchanged. In a similar way, the representativeness of vehicle speeds when passing through scenario 2 can be obtained by removing a minimum speed of 58km/h, and removing a maximum speed of 102km/h. Consequently, the vehicle speed passing through scenario 2 work zone can be obtained as 70-100 km/h, so the average speed can be approximately considered as 83 km/h. Compared with the design speed 100 km/h of this highway, the passing vehicle speed of scenario 2 work zone is reduced by about 15%. As for scenario 3 work zone, remove a minimum speed of 10km/h, and remove a maximum speed of 120km/h, then the vehicle speed passing through scenario 3 work zone can be obtained as 1078 km/h, so the average speed can be approximately considered as 40 km/h. Compared with the design speed 100 km/h of this highway, the passing vehicle speed of scenario 3 work zone is reduced by about 60%. According to the above logic in determining the vehicle speed when passing through these three different types of working zones for the highway ramp traffic lane, the following conclusions can be drawn about the relationship between vehicle speeds in work zones and the position of work zones: The work zone in Scenario 1 work zone has the lowest impact on vehicle speed – where it can be considered that vehicles will predominantly travel at the design highway speed. From the work zone layout of scenario 1 (shown in Figure 2), the reason for this situation may be that the higher elevation at the exit ramp, the drivers before exit the highway ramp have a wider field of vision, so they can perceive the work zone in advance, thus they have more time for route planning. Thus, scenario 1 work zone does not affect the vehicles which are exit the ramp to change lanes, which can lead to these vehicles quickly pass-through scenario 1 work zone, and then will not have a great impact on the main road vehicles’ speed. The speed of vehicles traveling on the main road is less affected by the ramp vehicles. Page 13 of 22 ENG5006 Technical Paper The work zone in scenario 2 show approximately a 15% reduction in vehicle speed, which is a stark contrast to scenario 3, where the reduction in the passing vehicle speed is approximately 60%. The reason for the larger speed reduction can be found in the work zone layout of scenario 3 (shown in Figure 4), fully closed main road lanes will greatly increase the traffic flow on the ramp traffic lane and reduce the area with which traffic can flow, a constant volume of traffic will naturally cause greater reductions in the travelling speed of vehicles. Mean speed when passing though workzone Error Bars donate S.E 140 Mean speed/ km/h 120 100 80 60 40 20 0 PRTP 1 PRTP 2 PRTP 3 PRTP 4 Scenario 1 PRTP 5 Scenario 2 PRTP 6 PRTP 7 PRTP 8 PRTP 9 PRTP 10 Scenario 3 Figure 11: Mean speed when passing through the work zone Braking distance According to the velocity and acceleration data, the braking distance of different participants for three different types of work zones can be determined, as shown in Figure 12. The method to calculate braking distance result is to subtract the longitudinal coordinates when the vehicle starts to decelerate from the longitudinal position of the work zone start point. The braking distance of each participant under the road conditions of three different work zone scenarios, subsequently lead to the following results: 1) The first situation is that the braking distance of scenario 1 work zone is bigger than the other two types of work zone, for all participants except for participant 1,2 and 4. 2) Conversely the braking distance of scenario 2 work zone is bigger than the other two types of work zone. This kind of situation happened 3 times out of 10 participants’ experiments, which is 30% of the total experiment. 3) Interestingly, there are no instances where the braking distance of scenario 3 work zone is bigger than the other two types of work zone which seems to imply scenario 3 work zone will have less effect on braking distance compared to the scenario 1 and scenario 2. Page 14 of 22 ENG5006 Technical Paper According to the above observations between the braking distance and different types of working zones, the following conclusions can be drawn about the relationship between the vehicle braking distance and the position of working zone: The observation of scenario 1 having greater braking distances can be attributed to vehicles on the main road and the ramp driving in the same direction which, reduces the need for lane changes. This in turn simplifies decision making as there is less pressure to perform more dangerous manoeuvres (such as merging into lanes with heavy traffic density). Additionally, greater braking distances mean there is a greater allowance for road users to adjust their travelling speed, which results in a more secure traffic flow, as well as more safe traffic conditions. In contrast, in Scenario 2, some of vehicles on the main road need to enter the ramp, so the frequency of lane changes will be more than in Scenario 1, which will have a certain impact on the vehicles in the straight line on the main road, and then reduce the braking distance of the vehicles tend to travel on the straight main road. The smaller braking distances that occur in the scenario 3 work zone may imply that there is a greater probability for more collisions to be encountered in this scenario. The reason may be that when the work zone completely closes of the main road, all traffic flows will choose the same diversion route. Combining the effect of the lateral road span as well as the forced diversion increases the difficulty for drivers to change lanes under heavy (and in some instances more complex) traffic conditions, as there is less room for error to avoid road accidents (Paolo and Sar, 2012). Therefore, it is easier to collide when changing lanes in scenario 3, which also corresponds to the results of the ‘Crash Frequency’ data analysis section. Braking distance for 10 participants experiments 400 Error Bars donate S.E Braking distance / m 350 300 250 200 150 100 50 0 PRTP 1 PRTP 2 PRTP 3 Scenario1 PRTP 4 PRTP 5 PRTP 6 Scenario2 PRTP 7 PRTP 8 PRTP 9 PRTP 10 Scenario3 Figure 12 The braking distance of work zones Page 15 of 22 ENG5006 Technical Paper Participant’s Feedback Based on the responses in the pre-questionnaire, it was revealed that the demographics of all participants were similar. The test group were primarily males, all within the age range of 24 years old to 28 years old, having an average of 4.2 years of driving experience (with the fewest being 2 and the most being 8), and all participants averaged approximately 7 to 8 driving hours per week, with about 1.5 hours per day. Additionally, all participants had minimal experience with VR simulations and using VR equipment. Given the similarities of all participants, it is difficult to ascertain the extent other external factors contributed to the behavioural differences. Unlike in previous research where it was found that there was correlation between the age group of the participants and how risky their driving behaviour was. (Moradpour et al., 2015), the narrow age range within the group likely resulted in there being a minimal correlation between the age differences within the participants and the differences in driving behaviour. The post-questionnaire revealed that some participants had issues controlling the vehicle, and as such required to adjust their driving to exhibit “conservative” (where they would take longer to arrive at freeway speed, and merge much earlier) behaviour than usual to avoid accidents. One of the participants had notable issues acclimatizing to the driving simulator, stating the control of the wheel felt “very un-intuitive” and the pedal sensitivity was very different to what they were used to. This “un-intuitive” control over the wheel was reflected in other participants where it was reported that they could not properly control the distance between the front and the next car, and there were occasional issues with lateral instability, which forced earlier braking than what they would typically do. Another participant reported to have issues with the braking system as it lacked “mechanical feel”, and as such, felt this issue in vehicle control caused the accident in scenario 3. In terms of realism, all participants did not feel any sense of vertigo or nausea, and all thought that the scene was a reasonable representation of real-life scenarios they have experienced. The same participant mentioned that some of the simulated traffic movements appeared to be unusual, although not “outside the realm of possibility based on some of the driving I have seen other people do”. It was reported that this unusual, simulated vehicle pattern forced a change in driving behaviour that was very different to what the participant naturally did. This could be explained by the issues in the experimental setup where there were some compatibility issues importing highly realistic vehicle physics into the simulation, which resulted in some participants having issues responding appropriately to the changing dynamics of the traffic. As the traffic flow was simulated, there were comments on how the flow of traffic, felt uneven, with multiple instances of “jittery movement” causing confusion on how to properly respond, as they were not used to this kind of environment. This caused a change in driving behaviour where the participants proceeded to exhibit more cautious driving behaviour (slower approach speeds and earlier merging) when approaching the Page 16 of 22 ENG5006 Technical Paper work zones in later trials. These responses contrasted the findings made in (Weidner et al., 2017), where it was previously concluded that VR will not exhibit significant difference in physiological responses or behavioural patterns in participants. LIMITATIONS AND SUGGESTIONS FOR FURTHER IMPROVEMENT The results from the research were pulled from a small scale of participants. Due to the time restrictions imposed upon this study, the remaining pool of participants were unable to participate in this study. Future study would involve a large sample size of participants with varying degrees of road (and driving) experience to produce a more thorough assessment to cover a wider distribution of driving behaviour for various reasons. Substantial lines of C# code were used in the creation of the driving simulation, which may have presented difficulties in the system’s rendering and processing capabilities. As reported in the feedback in the questionnaires, some participants experienced delays during the simulation, which in turn, may not be as reflective as real-life scenarios on the road. The equipment used to conduct the experiment was reported to have less of a “mechanical feel”, and as such required some participants to adjust their driving behaviour, which was atypical to how they would usually act on freeways. Improvements to the equipment used in similar studies where the participants are able to closely replicant their typical driving behavioural patterns (for instance, location and time of merging) is expected to yield interesting results where they may potentially exhibit less cautious driving behaviour in dangerous road scenarios. It is worth noting that if more unsafe driving patterns are recorded and are implemented in autonomous vehicle coding, it may potentially increase the safety of autonomous vehicles, as the algorithm may take a more cautious approach when processing real-time data of other people’s driving. CONCLUSIONS Based on the driving simulator, this study determined the influence on driving behaviour when the location of work zone near to on-ramp and off-ramp, respectively, and caused road closure, under the condition that all participants successfully completed the task. Drivers slowed down as they approached the work zone and accelerated quickly after passing, which is in line with previous research (Adeli, 2014). The longitudinal and lateral accelerations during vehicle travel were consistent with the Bivariate Pareto distribution model, with the probability of longitudinal acceleration being greater than lateral at low speeds. In the case of full lane closures, the vehicle braking distance is shortest, the speed is forced to the lowest and the collision rate is highest. Therefore, when more lanes are closed due to work zone, the traffic flow should be controlled to avoid low speeds and congestion. The work zone near the on-ramp in this study provides a longer braking distance than the work zone near the off-ramp, but as vehicles passing will be affected by vehicles entering the high speed from the ramp, the probability of a side-on collision that is too late to avoid is higher, so for such a work zone arrangement, it is even more important to ensure that vehicles pass at a suitably low speed. Page 17 of 22 ENG5006 Technical Paper Previous research has shown that narrower lanes can encourage drivers to actively slow down, so how to design for slowing down when ramps and work zones are in parallel could be an objective for future research. ACKNOWLEDGEMENTS This paper is supported by unit coordinator Dr Shaun Gregory, discipline coordinator Dr Tom Hughes, supervisor Nan Zheng and demonstrator Zheng Xu. The authors wish to acknowledge the discussion and contribution of the team members and the free use of MONASH library. Page 18 of 22 ENG5006 Technical Paper REFERENCES ADELI, A. 2014. Work zone speed analysis using driving simulator data, Morgan State University. AHAMMED, M. A., HASSAN, Y. & SAYED, T. A. 2008. Modeling driver behavior and safety on freeway merging areas. Journal of Transportation Engineering, 134, 370-377. ARTBA. 2022. National Work Zone Safety [Online]. 250 E Street SW, Suite 900, Washington, DC 20024: ARTBA. Available: https://workzonesafety.org/work-zone-data/ [Accessed 23/10 2022 ]. BLISSING, B. & BRUZELIUS, F. Exploring the suitability of virtual reality for driving simulation. Driving Simulation Conference 2018, 2018. 163-166. FFR, F. F. R. 2019. NATIONAL PARTNERSHIP AGREEMENT ON LAND TRANSPORT INFRASTRUCTURE PROJECTS. In: INFRASTRUCTURE (ed.). GOVERMENT, V. S. 2019. Traffic Volumes for Freeways and Arterial Roads [Online]. Available: https://vicroadsopendatavicroadsmaps.opendata.arcgis.com/datasets/5512df2ff41e4941bacf868053dbfba9_0/expl ore?location=-37.826634%2C144.931321%2C18.94 [Accessed 24/October 2022]. GU, X., ABDEL-ATY, M., XIANG, Q., CAI, Q. & YUAN, J. 2019. Utilizing UAV video data for in-depth analysis of drivers’ crash risk at interchange merging areas. Accident Analysis & Prevention, 123, 159-169. HU, J., HE, L. & WANG, R. 2020. Safety evaluation of freeway interchange merging areas based on driver workload theory. Science progress, 103, 0036850420940878. HUSSAIN, Q., ALHAJYASEEN, W. K., PIRDAVANI, A., REINOLSMANN, N., BRIJS, K. & BRIJS, T. 2019. Speed perception and actual speed in a driving simulator and real-world: A validation study. Transportation research part F: traffic psychology and behaviour, 62, 637-650. LANG, Y., WEI, L., XU, F., ZHAO, Y. & YU, L.-F. Synthesizing personalized training programs for improving driving habits via virtual reality. 2018 IEEE Conference on Virtual Reality and 3D User Interfaces (VR), 2018. IEEE, 297-304. MCCARTT, A. T., NORTHRUP, V. S. & RETTING, R. A. 2004. Types and characteristics of ramp-related motor vehicle crashes on urban interstate roadways in Northern Virginia. Journal of Safety Research, 35, 107-114. MORADPOUR, S., WU, S. & LEU, M. C. Use of traffic simulators to determine driver response to work zone configurations. Proceedings of the International Annual Conference of the American Society for Engineering Management., 2015. American Society for Engineering Management (ASEM), 1. PAOLO, P. & SAR, D. 2012. Driving speed behaviour approaching road work zones on two-lane rural roads. Procedia-Social and Behavioral Sciences, 53, 672-681. SINGH, S. 2015. Critical reasons for crashes investigated in the national motor vehicle crash causation survey. VICROAD.VIC.GOV.AU. 2021. Crash statistics: VicRoads [Online]. Available: https://www.vicroads.vic.gov.au/safety-and-road-rules/safety-statistics/crash-statistics [Accessed 10 October 2022]. WEIDNER, F., HOESCH, A., POESCHL, S. & BROLL, W. Comparing VR and non-VR driving simulations: An experimental user study. 2017 IEEE Virtual Reality (VR), 2017. IEEE, 281-282. Page 19 of 22 ENG5006 Technical Paper XU, Z., ZOU, X., OH, T. & VU, H. L. 2021. Studying freeway merging conflicts using virtual reality technology. Journal of safety research, 76, 16-29. ZHANG, Y., ZOU, Y., WANG, Y., WU, L. & HAN, W. 2022. Understanding the merging behavior patterns and evolutionary mechanism at freeway on-Ramps. Journal of Intelligent Transportation Systems, 1-14. Page 20 of 22 ENG5006 Technical Paper APPENDIX APPENDIX A. Lane change trajectory of vehicle through Scenario 1 APPENDIX B. Lane change trajectory of vehicle through Scenario 2 Page 21 of 22 ENG5006 Technical Paper APPENDIX C. Lane change trajectory of vehicle through Scenario 3 APPENDIX D. Questionnaire (pre and post) Questionnaire (pre and post) Page 22 of 22 Pre-Questionnaire Participant No: Date: Please complete the following questionnaire with specific regard to the respective enquiry, by placing a cross over the appropriate response. For numerical responses, round down to the lowest whole number if necessary (e.g. 2.9 years = 2 years) 1. What is your gender? Male Female Trans Bisexual Agender (no gender) Other, if so please specify………………………………….. 2. What is your age Group? 18 to 23 24 to 29 30 to 35 36 to 41 More than 41 3. What is your highest level of education completed or currently undergone? Highschool or less Associate degree Bachelors Masters PhD 4. Are you currently working (full time/ part time / casual) or volunteering? Yes No 5. What type of driving license do you have? No License Learner’s Permit P1 Probationary License (Red Ps) P2 Probationary License (Green Ps) Full License Overseas License, if so, please specify country………………. 6. How long have you had your license? 0 to 1 year 1 to 2 years 2 to 3 years 3 to 4 years More than 4 years 7. Approximately often do you drive? Daily 3 to 5 days a week Once a week 2 to 5 times a month Only for a few occasions per year None Other, if so please specify ………………………………. 8. Approximately many hours per day do you drive? 0 to 1 hour 1 to 2 hours 2 to 3 hours 3 to 4 hours More than 4 hours Not Applicable. 9. How frequently do you use freeways? Daily 3 to 5 days a week Once a week 2 to 5 times a month Only for a few occasions per year Never Other, if so please specify ………………………………. 10. How often have you come across work zones in the past 12 months? Daily 3 to 5 days a week Once a week 2 to 5 times a month Only for a few occasions per year Never Other, if so please specify ………………………………. 11. How often have you come across work zones on freeways in the past 12 months? Daily 3 to 5 days a week Once a week 2 to 5 times a month Only for a few occasions per year Never Other, if so please specify ………………………………. 12. If required to merge, how would you typically react under normal free flowing traffic (on normal roads)? As soon as possible Around halfway towards the point at which I need to merge At the last possible moment. 13. If required to merge, how would you typically react under normal free flowing traffic (on freeways)? As soon as possible Around halfway towards the point at which I need to merge At the last possible moment. 14. If required to slow down, how would you typically react under normal free flowing traffic (on normal roads)? As soon as possible Around halfway towards the point at which I need to slow down At the last possible moment. 15. If required to slow down, how would you typically react under normal free flowing traffic (on freeways)? As soon as possible Around halfway towards the point at which I need to slow down Near the last possible moment 16. Do you think you have good reaction speeds towards external road stimuli such as signs? I always/often react immediately I am sometimes slow to react I remember many occasions where I was slow to react 17. How much experience do you have with VR Simulation and Equipment? I use it often (lots of experience) I have used it before (some experience) It is brand new to me (minimal experience) 18. Do you often experience motion sickness or travel sickness? Very often Only on specific occasions (please specify________________ _______________________________________________) No Post-Questionnaire Participant No: Date: Please complete the following questionnaire with specific regard to the respective enquiry, by circling over the appropriate response The simulation was similar to the experience of driving on a freeway Strongly Agree Agree Unsure Disagree Strongly Disagree It was easy to control the speed of the vehicle Strongly Agree Agree Unsure Disagree Strongly Disagree I felt comfortable using the brake pedal Strongly Agree Agree Unsure Disagree Strongly Disagree I felt comfortable using the gas (accelerator) pedal Strongly Agree Agree Unsure Disagree Strongly Disagree I felt comfortable using the steering wheel Strongly Agree Agree Unsure Disagree Strongly Disagree It was easy to control the lateral movement of the vehicle Strongly Agree Agree Unsure Disagree Strongly Disagree I found it easy merge into other lanes Strongly Agree Agree Unsure Disagree Strongly Disagree The simulated surrounding environment and terrain around the freeway felt reasonably realistic Strongly Agree Agree Unsure Disagree Strongly Disagree The simulated surrounding environment and terrain did not influence my driving Strongly Agree Agree Unsure Disagree Strongly Disagree I could easily recognise the start of the work zone Strongly Agree Agree Unsure Disagree Strongly Disagree I could easily recognise the end of the work zone Strongly Agree Agree Unsure Disagree Strongly Disagree I found it easy to drive safely in the simulated traffic condition Strongly Agree Agree Unsure Disagree Strongly Disagree The roads felt reasonably realistic Strongly Agree Agree Unsure Disagree Strongly Disagree I could easily see the signs Strongly Agree Agree Unsure Disagree Strongly Disagree Additional Feedback and Comments about the simulation