A review of virtual reality applications in transportation - Dr. Lim Jiong Kang


Abstract: Virtual reality technology to the development of transportation industry brings new opportunities and challenges, the virtual reality in traffic simulation, traffic accident simulation and virtual driving system, traffic results show, traffic behavior psychological research, the virtual traffic equipment design and maintenance aspects of application situation were summarized, analyzed the problems existing in the application of industry, and together with the present situation of China's transportation, The trend of virtual reality application in transportation is forecasted.

Key words: problem driven; Virtual driving; Traffic simulation; Virtual reality; The transportation

The introduction

Virtual Reality (VR)[1] is a Virtual environment with a certain range of realistic visual, auditory and tactile integration, which is generated by modern technology with computer technology as the core. Users can interact with and influence objects in the Virtual environment in a natural way with the help of necessary equipment. In order to get the experience and experience of the actual environment. After nearly thirty years of development, the basic concepts and methods of virtual reality have been preliminarily formed, and encouraging application results have been achieved in many industries. "Virtual reality +" [2] has become a new trend. Virtual reality technology is more and more applied to the planning and decision-making of transportation, design evaluation, training experience and achievement display and other aspects, and has become an important technology that can be adopted and assisted the development of the transportation industry.

Overview of virtual reality transportation applications

Transportation is one of the important areas related to national economy, people's livelihood and national strategy. Traditional digital transportation has made great progress in reducing traffic congestion, improving traffic safety, making full use of transportation resources, improving transportation conditions and improving the quality of public services. The development of virtual reality technology has further broken the limitation of people's expression and processing of geospatial information, so that digital traffic can be displayed in a more intuitive way, managed in a more efficient way, and processed in a more intelligent way.

At present, there is a contradiction between the rapid development of virtual reality technology and the slow application of transportation industry. The international research on the application of virtual reality in transportation has just started, and most of the work is still in the scatter research stage of the development and application of traffic simulation software, the development of vehicle driving simulator, and the visualization of traffic data. Domestic virtual reality technology has been increasingly applied to the transportation industry, especially in navigation simulator, virtual-real fusion traffic scene monitoring, rail transit pedestrian simulation has certain technical advantages. However, in general, there is a lack of special research and continuous tracking of the application of VIRTUAL reality in transportation at home and abroad, and a lack of systematic summary of the application status of virtual reality in transportation.

At present and in the future, the strategic task of China's transportation is to accelerate the development of comprehensive transportation, intelligent transportation, green transportation and safe transportation. The essence of comprehensive transportation is to rationally allocate and optimize the integration of transportation resources to give full play to its overall scale efficiency. The core of intelligent transportation is to improve the service efficiency and quality of transportation with intelligence as the traction. The key of green transportation is to optimize the consumption structure and realize intensive development in transportation planning, construction, operation and maintenance. Safe traffic is the focus of the establishment of hidden danger screening and management system and safety prevention and control system. The "four transportation" are interrelated and complementary, which together constitute an organic system to promote the modernization of transportation development. At the same time, it also presents new opportunities and challenges for the application of virtual reality transportation.

Combined with the demands of the development of the transportation modernization in our country and current situation of business papers for virtual reality transportation application research were reviewed, as shown in figure 1, with emphasis on the traffic of the virtual reality simulation, traffic accident simulation and virtual driving system, traffic results show, traffic behavior psychological research, typical applications such as virtual transportation equipment design and maintenance, The existing problems in the application are analyzed, and the research directions that can be focused on in the future are prospected.


Figure 1 virtual reality traffic application direction

2 virtual reality traffic simulation

Traffic simulation is a research process of using computer technology to establish a computer model that can replace the actual traffic system [3]. Traffic simulation of virtual reality, the use of virtual reality technology and equipment to build visualization traffic scene, represent the characteristics of the real traffic system, analysis the behavior of various setting under the condition of traffic system, through the model test results of simulation and human-computer interaction feedback, seeking reality the traffic problem, the optimal solution to support all kinds of transportation planning, design, evaluation of the effect of the management plan.

The realization of the virtual reality simulation usually includes scene modeling, microscopic traffic simulation and dynamic scene display and human-computer interaction design, etc., in which microscopic traffic modeling and simulation is one of the basic content of virtual reality simulation, including carriage tool behavior modeling, behavior modeling of the traffic participants, modeling, traffic supply and traffic demand management model, etc. [4]. At present, foreign traffic simulation software is mainly introduced in China, including Paramics from Quadstone in Scotland, Vissim from PTV in Germany, TansModele from Caliper in the United States, etc. Yi Tao and Xiong Jian [5] combined traffic flow simulation with driving simulator display, and added simulated traffic flow phenomena into the visual scene to support research on driver behavior and automotive ergonomics. Wang Jiangfeng et al. [6] studied the minimum safe distance of vehicle lane change in virtual reality, established the co-simulation model of driver behavior, and verified it in the virtual environment. Xia Ping [7] reflected the objective interference factors of "safety + energy saving" driving in the real traffic environment in the visual scene, providing a virtual reality platform for the research and driving training of safety and energy saving driving. In 2014, Yang Qian [8] implemented and evaluated multiple dynamic induction strategies using q-Paramics micro-simulation platform. Fan Ran [9] used Vissim to carry out simulation of microscopic traffic intersections, and Synchro software to optimize signal timing and timing, and carried out application verification of Dawangqiao intersection in Beijing.

According to different objects, traffic simulation also includes rail transit simulation [10], pedestrian simulation [11], non-motor vehicle simulation, maritime traffic simulation [12], storage and logistics operation process simulation, traffic sign line simulation, air traffic simulation, etc. Liu Ying [13] introduced virtual reality into railway line management to form a simulated and interactive railway line virtual scene. Chen Hongchuan [14] took the subway platform environment as an example to simulate crowd evacuation in the virtual traffic environment based on OSG, and verified the proposed crowd behavior model based on signal vector. Li Xingxing [15] studied the driving behavior models of non-motor vehicles such as bicycles and electric vehicles, defined the virtual lanes, car-following behavior and lane change behavior of non-motor vehicles, and calibrated the model parameters with actual survey data and empirical values. Qin Tianbao and Zhang Yi [16] made use of virtual reality simulation method to assist gate planning. By examining the length and waiting time of vehicles at the gate obtained by simulation, qin Tianbao and Zhang Yi [16] intuitively evaluated gate service level and gate buffer design, making up for the deficiency of traditional analysis method. In 2014, Chen Na et al. [17] proposed a virtual reality-based experimental analysis method for traffic sign perception. Several drivers were randomly selected to visually recognize and compare traffic signs in the virtual environment, so as to obtain the setting value of signs and lines with the best visual perception.

At present, more and more virtual reality methods and devices are applied to traffic simulation, which improves users' perception, insight and prediction ability of traffic scenes to a certain extent. However, there are still some problems such as lack of core software of traffic simulation, inconsistencies between foreign software and domestic transportation status, unclear traffic problems to be solved, insufficient application of immersive perception, lack of killer application, lack of domestic practice data support and so on. Compared with traditional traffic simulation methods, virtual reality traffic simulation pays more attention to human perception and feedback, and is suitable for traffic system planning decisions and design evaluation applications emphasizing user experience.

3. Traffic accident simulation

Traffic accident simulation refers to the use of computer technology to reproduce the occurrence and development process of traffic accidents in the virtual environment [18], and carry out case analysis and deduction to a certain extent with the support of sampling data. The occurrence of traffic accidents is often completed in an instant, many details are not known, easy to cause illusion. It is very important to find out the truth of traffic accident fairly, justly and closely, analyze the cause of the accident and identify the responsibility of the accident, which makes it necessary to use virtual reality to simulate and reproduce the traffic accident and assist the analysis.

The realization of traffic accident simulation usually includes field measurement, accident analysis, scene reconstruction, process simulation and case analysis. The data of people, cars, roads, scenes and traces in the accident site are obtained by field measurement, which provides data basis for accident simulation and case analysis. He Xutang [19] applied the image ranging technology to the rapid processing of traffic accidents to realize the rapid acquisition of accident site data. By collecting the 360° real panorama of the accident scene, Domestic Gold Vision and companies can reproduce the real scene of the accident scene directly in the virtual scene, and support the data measurement, dimension marking and paintbrush marking on the scene. Accident analysis is based on a large number of real vehicle crash experiments, using forward simulation and iterative algorithm, by verifying whether the simulated traces are consistent with the actual accident site traces to infer the speed before and after the collision. At present, mature traffic accident analysis software mainly includes CRASH and IMPAC from the United States, PC-Crash from GRAZ University of Technology in Austria, J2DACS and CARS from Japan, WACCAR from Germany and ANAC from France, etc. Zou Tiefang et al. [20] proposed a step by step reappearance method of vehicle sideslip accident by using PC-Crash software. Zhu Lusheng et al. [21] took a real car-person collision accident as an example, used PC-Crash software to build a car-person collision accident model, and used the orthogonal test method to fit the model parameters. Chang 'an University independently developed the Road Traffic Accident Analysis, Calculation and Reproduction System (TACAR). Shu Qiang [22] used TACAR and the road traffic accident scene map drawing system to carry out three-dimensional reproduction and analysis of traffic accident cases. Scene reconstruction is used to construct a virtual environment for accident reproduction, and three-dimensional reconstruction is carried out for objects such as people, cars (ships), roads (channels), terrain, traffic auxiliary facilities, important buildings and sky. Process simulation is based on the data obtained from field measurement and accident analysis to realize 3d scene display and interactive control. In 2003, Zhang Wei et al. [23] from Tsinghua University realized 3d scene simulation of road traffic accidents by using OpenGL, when the author only thought that 3D simulation was only the final link of traffic accident analysis. Yang Na [24] used Pro/Engineer to reproduce the calculation results of vehicle dynamics at the moment of collision in the virtual environment. Xiong Jing [25] used Virtools software to develop a virtual representation system of traffic accidents to reconstruct and display the scene and process of road traffic accidents. Wei Xiao [26] studied the operating mechanism of the cyclist in the accident of one or two wheelers, and used OSG to realize the three-dimensional repetition of the accident of car collision with two wheelers, providing effective data support for accident analysis. Case analysis is based on the occurrence process of repeated accidents, according to the national laws and regulations to determine the process of accident liability. 2011, Wei Chao [27] to a controversial for years major accident reappearance and case analysis, to collect field road, environment and key data of the vehicle, using PC - Crash accident reconstruction, the accident reconstruction result and accident data validation, process validation accident from various angles, implements the logic and evidence. In addition, Tu Haiyang and Yuan Zhangxin [28] designed and implemented a simulation system for ship traffic accident recurrence based on ship handling simulator, which provides objective basis for improving Marine authorities' investigation and summary of accidents.

At present, the reconstruction and analysis of traffic accidents have received full attention. Some domestic teams have developed mature technologies and solutions to form a three-dimensional model base and case resource base of traffic accidents on a certain scale. However, there are still some problems, such as lack of detailed features of the model, difficult to verify the reliability of the simulation results, lack of core data of crash test, insufficient consideration of human behavioral psychological factors, poor portability of solving force-case, etc. The solution of these problems will help to promote the further application of traffic accident simulation and analysis technology.

4 virtual driving system

Virtual driving system is to make use of image generation, vehicle dynamics, human-computer interaction and other technologies, so that the experirer can feel the driving experience close to real sight, hearing and motion sensation in the virtual driving environment. The limited training conditions and situations encountered by vehicles such as cars, trains, airplanes and ships limit the trainees' cognition of dealing with complex situations. The virtual driving system can simulate various traffic environments and conditions to reduce training costs and actual operation risks and improve training efficiency.

In 1970, Japan legislated that car driving training schools must be equipped with car driving simulators. Under European law, operating drivers must spend seven hours a year on simulators to train in emergency traffic situations. In 2015, the New Zealand Automobile Association officially launched an online virtual driving system for overseas tourists [29], which is the most vivid way for overseas tourists to understand New Zealand's driving rules so far. Su Guohui et al. [30] made use of OpenGL to realize the virtual scene change of car THREE-DIMENSIONAL instrument and car driving. According to the control of oil pressure and brake pedal, the parameter display of virtual car instrument was changed in real time, and the motion of virtual car in 3D scene was realized based on the parameters. Chai Shan et al. [31] established a virtual driving system including engine model, driveline model, clutch model, brake system model, vehicle driving speed model and steering system model, which can accurately simulate the dynamic response of a vehicle under driving conditions such as starting, acceleration, steering and braking. By using the driving simulator, Huizhi Technology [32] can provide users with special driving behavior experiences such as drunk driving, speeding, overcrowding, overload and fatigue driving, and provide a new means for safety training of operating vehicle drivers.

Virtual driving system also includes bicycle, rail transit, flight, navigation, engineering vehicle virtual driving platform and so on. Fu Baichuan et al. [33] introduced the concept of freedom of human movement and proposed a motion simulator algorithm applicable to the bicycle two-wheeled vehicle simulator, which was applied to the first six-degree-of-freedom bicycle simulator in China to provide drivers with a good sense of movement. Guo Xuejing [34] designed and implemented a motorcycle driving simulation system to realize collision detection and terrain following in the visual system, and carried out simulation driving tests on a six-degree-of-freedom motion simulator to realize the sense of reality and immersion of motorcycle virtual driving. Rail transit virtual driving system is often used in rail vehicle driving training, fault and emergency treatment training, train rescue and rescue training, train scheduling and signal control training, etc. In 2012, Wu Haichao and zhang security [35] developed CRH3 bullet train virtual driving simulation system, can show invisible, do not touch, do not into the train parts of the structure, layout and connection mode, easily set not often met in reality and use physical failure mode set is very troublesome, to improve the training efficiency, reduces the cost. Beijing University of Aeronautics and Astronautics, Nanjing University of Aeronautics and Astronautics, Chinese Academy of Sciences and other units [36] have made contributions to the aerospace simulator, and Dalian Maritime University, Shanghai Maritime University, Jimei University and other units [37-38] have achieved good results in the development and application of navigation simulator. Engineering vehicle virtual driving system is helpful to train the skills of engineering vehicle operators. Yao Meijiao and Zhang Deyu [39] designed and implemented a tracked vehicle driving training system, including dynamic simulation, visual simulation, sound system, instrument system, etc. Lu Mengmeng [40] used Vega to develop a desktop-based virtual training system for quayside container crane operators, which realized the simulation of crane operation mechanism and loading and unloading process.

At present, flight, navigation and motor vehicle driving simulation systems have been widely used in the industry. Driving simulation systems for bicycles, engineering vehicles and military vehicles have also been promoted in different fields, but most of the existing systems still stay at the level of experience driving. Moreover, there are some problems such as high cost, poor immersion, lack of interference factors of real traffic environment, lack of man-machine interaction, and the guiding effect needs to be verified.

5 virtual reality display of transportation achievements

New work keeps emerging with the rapid development of transportation, and the new achievement with a display in the form of new requirements, using holographic imaging, augmented reality, interactive projection, digital sand table, technology and equipment, such as virtual reality helmet to personalized show the results of the transportation and products, to improve results show the penetrating power of transportation.

Results display is mainly used in traffic engineering bidding, traffic planning display, new vehicle design release, transportation safety science and other aspects. Huang Xiaomei [41] made a virtual animation display of rail transit and the past, present and future development of cities, which enhanced people's understanding and support for rail transit construction. Zhao Yongguo et al. [42] took Xinjiang highway as an example to realize the road traffic electronic sand table display based on 3D GIS, which dynamically displayed the real terrain and geological characteristics along the xinjiang highway network, providing scientific basis and reference for highway planning and decision-making. BMW launched BMW 7 Series with the help of holographic projection technology [43], and the effect was shocking. In the chengdu Auto Show in 2015, Mitsubishi Motors [44] used a real car test drive experience simulator to conduct a simulated test drive, so that drivers could experience the driving experience of the car on roads, snow and ice, deserts, mountains and other roads without leaving the exhibition hall. Toyota motor of Japan is also keen on using virtual reality technology to display and release new products. They have designed an augmented reality product catalog [45] to assist vehicle sales negotiations and make negotiations without display vehicles more convenient. In 2015, Toyota held a mixed reality new car press conference for the new car Corolla Fielder in Tokyo, Japan [46], which adopted a 360-degree camera for filming, and users could rotate the picture at will through the mobile phone in the field, thus realizing the real-time mixed presentation of the press conference on-site and post-production effects.

Virtual reality provides new equipment and means for the display of transportation results, but in the specific application process, it is necessary to consider the story of the display theme, the economy of cost, the fit of technology, the participation of the audience, the effectiveness of the display and the penetration of the effect.

6. Research on traffic behavior psychology in virtual reality

People, car (ship), road (waterway) and environment constitute the four elements of traffic. Among them, people are the main body of traffic and the most complex part of the four elements. The virtual reality is used to study the behavior, psychology and their relationship of transportation people, so as to provide methods and ideas for screening high-risk groups and preventing transportation accidents.

Analysis and study of driver psychology will help to understand driver behavior and provide guidance for traffic management and safety improvement. On the one hand, it studies the driver's cognitive process, including feeling, perception, attention, etc. Li Wei [47] studied the evacuation behavior of crowds under emergency conditions in virtual environment, realized the dynamic evacuation of crowds under different conditions, and provided data support for the formulation of optimal evacuation strategy in emergencies. Wei Lang etc. [48] on drivers' road safety evaluation research, organize pilot of 53 virtual level 3 highway field cognitive evaluation experiments of 210 national highway, with three levels of road safety based on the actual road and cognitive factors, compares the membership function of fuzzy evaluation, proves the feasibility of virtual reality in the driver's cognitive evaluation of road safety. Ren Yanming [49] applied virtual reality to the test of color traffic guidance system in Beijing, simulated the influence of different meteorological conditions and different speeds on the color identification of traffic guidance signs, and used the test data and analysis to optimize the color traffic guidance system to make it more in line with the real traffic requirements. Zhang Yonggang [50], starting from the driver's speed control, distance maintaining and steering wheel control behavior, proposed the contour fusion method of extracting the boundary feature of the cab steering wheel to realize the identification of drivers' illegal driving behavior based on hand features, which laid a foundation for the intelligent analysis of the abnormal behavior of long-distance bus drivers. The other is the study of the driver's emotional process, including emotion, emotion, attitude, etc. To explore the driving cause of anger and its influence on traffic accident, in 2014, wuhan university of science and technology YanLiXin [51] was designed based on vehicle driving simulator driver anger induced experimental scheme, construction of typical driving anger induced traffic scene, through subjective questionnaire and statistical analysis, the physiological index to evaluate induced experimental induced effect.

The immersive, interactive and imaginative features of virtual reality provide appropriate methods and means for the research of traffic behavior psychology, save sampling cost, reduce the risk of actual experiments, and realize the repeatability of event construction. However, the reliability verification of virtual and real environment experiments is one of the main problems currently faced.

Virtual design and maintenance of transportation equipment

Transportation equipment usually has a long development cycle, high design cost, high development risk and complex maintenance process. Virtual design and maintenance provide support for saving product design cost, reducing design risk, reducing maintenance cost and improving industry competitiveness.

[52] in 2013, ford motor company in 3 d virtual imaging in the CAVE to build a new car, vehicle three-dimensional image projection to studio three walls and a roof, with the help of a special polarized glasses and mobile induction infrared system, engineers can enter the virtual vehicle internal facilities, such as adjusting the rearview mirror or place the bottle in the door store content box, Instead of spending a lot of time and resources building a complex model of a real car, thousands of design details can be optimized through virtual design. Ford [53] also used 3D printing technology to make the engine cover of 2015 Ford Mustang, and quickly produced the cylinder head, intake manifold, exhaust passage and other parts with high sharing rate prototypes, saving millions of dollars of development costs and a lot of development time. Emu is a large complex product with complex system, advanced technology and precise equipment. The traditional physical prototype training and maintenance cannot meet the needs of mass maintenance training for EMU due to the limited factors such as the number of equipment, training cost and training content. Zhou Shaoze et al. [54] realized the virtual maintenance of emU turn frame and expressed the maintenance process of complex equipment with interactive information, which improved the training effect. Lu Senwei et al. [55] realized the virtual disassembly, maintenance and repair of Marine motors with script programming of Virtools, which has the advantages of small risk, high efficiency, small mechanical wear and convenient training. Mou Guoliang et al. [56] built a desktop diesel engine virtual maintenance training system based on EON virtual platform to guide trainees to carry out diesel engine maintenance training and provide a reference for high-efficiency and low-cost equipment maintenance training.

Virtual design and maintenance can predict, evaluate and optimize each stage of product development and maintenance in real time, which brings new means and concepts to industrial design of transportation equipment. It is beneficial to enhance industrial design means, improve product design quality, reduce the cost of sample trial production, and facilitate after-sales maintenance.

Eight other

The applications of virtual reality in the transportation industry also include visualization of traffic engineering construction process, analysis and visualization of traffic operation data, simulation and exercise of emergency traffic plan, and traffic scene monitoring of virtual and real integration, etc. Hong Lei [57] proposed the whole-life-cycle management framework of bridge engineering based on Building Information Modeling (BIM). Taking Guiyang Zhushui footbridge and Hubei East Hubei Yangtze River Bridge as the engineering background, he studied the application of BIM in different stages of bridge engineering in scheme, design, construction and operation. Li Junsong et al. [58] studied the application of BIM in the whole life cycle of railway tunnel engineering based on the Shikwu Mountain high-risk tunnel project of Baolanke, so that the engineering information can be effectively used and managed in the whole life cycle, so as to optimize the design scheme, strictly control the construction process and improve the operation efficiency. Ishida et al. [59] of The University of Tokyo, Japan, combined with GIS visualization technology, designed and completed the "Digital Tokyo" project, which visualized and navigated the buildings and roads in Tokyo. In 2012, Google[60] began to launch real-time traffic data visualization for London, Washington and other cities, providing data support for residents' convenient travel. Zhou Huijuan et al. [61] unified the detection data of high-speed comprehensive detection trains in a THREE-DIMENSIONAL GIS visualization system by using virtual reality and multimedia technology.

9 Advantage Analysis

The framework of virtual reality traffic and transportation application is shown in Figure 2. On the basis of multi-source data collection of traffic operation, modeling software such as 3DS Max and Trans CAD is used to model 3d scenes and objects. VISSIM, Paramics, Legion, STEPS, Traffic simulation software such as PC-Crash conducts modeling of microscopic traffic objects and behaviors, performs visual display and interactive control based on virtual reality engine, and finally supports practical applications such as congestion management, overspeed, overloading and overlimit management, traffic accident simulation, traffic accident emergency plan simulation, and communication results display.

Virtual reality provides simulation and analysis of all links of traffic management and service, and through deduction and display in virtual environment, provides auxiliary decision support for traffic supervisors in traffic design, planning, monitoring, management, operation and maintenance and other aspects. Virtual reality has opened up a broad development space for traffic design, such as intersection design, road landscape design, interchange road design, etc. Virtual reality technology can make two-dimensional graphics three-dimensional, intuitive and sequential, so as to greatly improve the efficiency and scientificity of design, and avoid blindness and resource waste during construction. Virtual reality has natural advantages in driver psychological testing, driver training and assessment, etc. Compared with the traditional traffic behavior theory research method in the form of questionnaire survey, the immersive interactive environment can obtain more scientific psychological data of traffic behavior. Virtual reality is helpful to improve the management level of traffic and transportation safety. Through the simulation and reproduction of traffic and transportation safety events, it is helpful to analyze the cause of the accident, clarify the responsibility of the accident, optimize the accident warning mechanism, improve the emergency response level, and can be used for warning education of traffic and transportation safety.


Figure 2. Realization framework of virtual reality transportation application

10 Problems

The rapid development of transportation has brought new problems, and virtual reality has provided new methods and means to solve these problems. With deepening transportation application of virtual reality, simulation and virtual driving in traffic simulation, traffic accident, the results show, traffic behavior, psychological research has obtained certain breakthrough, but there are still some problems to be solved, the solution of these problems will help to promote practical and development in the field of virtual reality in transportation.

(1) Lack of attention to practical transportation problems: Virtual reality applications in the field of transportation is most in the audio-visual display stage at present, the lack of governance, speeding the overcrowding overrun overload management, traffic transportation reality problem such as emergency treatment, travel services, not form a virtual reality application of the killer application of transportation, lack and transportation management and service in combination with the deep real business, How to use virtual reality to find and solve the practical problems of transportation is one of the first problems to be faced.

(2) Research on micro traffic simulation in line with China's traffic situation is insufficient: Most of the existing traffic simulation applications are based on the mature simulation software of foreign countries. They do not take into account the current situation of domestic traffic, such as parking occupying the lane, mixed flow between people and cars, the increase of electric vehicles, and pedestrians' blind compliance. The correctness of the simulation model lacks the test of domestic practice data, and the simulation results cannot well reflect the current situation of Chinese traffic.

(3) Reliability verification of virtual reality transportation applications: Reliability verification is one of the basic problems of virtual reality applications. Only the simulation results can withstand verification and evaluation, can effectively support the management and service of transportation. With the support of massive traffic operation data, it is one of the important issues to be studied whether the quantitative methods and measures can be found to evaluate the traffic application of virtual reality.

(4) Lack of continuous tracking and specialized research on virtual reality transportation applications: At present, the application of virtual reality transportation research has just started, the overall is still in a state of scatter, failed to form effective impetus to the development of the transportation sector, also limits the domestic and foreign advanced applications in the field of virtual reality technology in transportation, the lack of transport problems, and virtual reality of frontier technologies continue to track, Lack of professional teams focused on virtual reality traffic applications.

11 Development trend and direction

Combined with the latest characteristics of virtual reality technology and the actual traffic and transportation business needs, the future directions of virtual reality transportation applications that can be substantially promoted are prospected.

(1) Virtual and real integration monitoring of transportation hub: The virtual-real fusion traffic scene monitoring refers to the use of augmented reality and video fusion technology to integrate the originally discrete videos of multiple surveillance cameras into a unified THREE-DIMENSIONAL scene, so as to realize continuous observation of a large area of key traffic scenes such as Bridges, tunnels, ports, airports, rails, highways and transportation hubs. It solves the problems that traditional video wall scheme is difficult to reconstruct the complete space, and the monitoring personnel are difficult to understand and respond, and supports automatic patrol, historical video playback, multi-source data fusion display, intelligent video analysis and other functions.

(2) Practical problem driven traffic simulation application: Surrounding urban congestion management, evaluation of the effects of traffic events, transit network planning, speeding the overcrowding overrun overload control, traffic safety and the environment benefit evaluation of transportation realities, represent the real traffic system characteristics, analysis of setting under the condition of the traffic system behavior, seeking reality traffic problem of the optimal solution, to evaluate the effect of all kinds of planning, design, To promote the solution of real problems in transportation management and service.

(3) emergency transportation plan design, simulation and evaluation: for subway fire spread and the crowd evacuation, rail transit emergency, tunnels culvert safety emergency, traffic hub crowd monitoring and emergency, emergency transportation evacuation plans for the large-scale activities of simulation research, practice and evaluation, improve the ability of dealing with the traffic emergency management department, reduce the loss caused by emergencies.

(4) in accordance with the present situation of China's transportation: microscopic traffic simulation research on parking encroachments, parking guidance, mixed traffic, electric drive, pedestrians blindly follow, such as improper driving traffic behavior modeling and parameter validation study with Chinese characteristics, consider people, bicycles and motor traffic mixed traffic patterns influence each other, study conforms to the present situation of China's transportation microscopic traffic simulation key technology.

(5) Immersive transportation experience and evaluation: An immersive virtual reality transportation environment is constructed to enable users to experience, empathize and interact naturally in the virtual environment. It is used to support the research of public transportation comfort evaluation, experience and evaluation of road subject and ancillary facilities, abnormal driving behavior experience, transportation safety education, driver psychology test and behavior analysis, etc.

To sum up, the core of the application and development of VIRTUAL reality in the field of transportation is the discovery and solution of practical problems in transportation. Only the technology that can really solve the practical problems in the industry has vitality and can further promote the innovation and development of virtual reality technology.

Conclusion 12

The rapid development of transportation brings new carriers and problems to virtual reality, and virtual reality brings new methods and means to the construction and development of transportation. Paper summarizes the virtual reality technology in traffic simulation, traffic accidents, traffic simulation and virtual driving system results show virtual traffic, traffic behavior psychological research, the present situation of the application of equipment design and maintenance, analysis of the current problems existing in industry application, combined with the transportation in our country the status quo, on the possible development trend and direction was prospected.