n September 7, CCTV 13 news broadcasting studio reported that "the first pilot area of vehicle network in Wuxi, Jiangsu Province was unveiled". The scene of cooperation between vehicles and vehicles, vehicles and people, vehicles and roads, vehicles and service platforms has become a hot spot. Among them, the "active and intelligent" series of road scenarios jointly created by China Mobile, Ministry of Public Security Traffic Office, Wuxi Traffic Police, Huawei, Tian'an Zhilian, Saikang Jiaoan and other units of the strategic partners of the project team of the National Pilot Area of Vehicle Networking, are on the road of achievement promotion through demonstration application. China Road Traffic Safety Think Tank Committee Wechat Public Number has released scenarios, three-level traffic signal guidance system：

1. Pain Points of Traditional Traffic Signal Organization Model：

When referring to traffic signals, people generally associate the traffic lights (traffic lights) at road intersections, which often do not associate traffic signs, markings and police command gestures with "traffic signals". Therefore, a large number of cities in the traffic congestion management work, blindly make articles on the signal lights, green wave, timing, brain, superbrain, busy and happy. In fact? In the whole road traffic organization, traffic lights are only a late comer. They are far less prepositional and important than the three "traffic signals" of police command gestures, traffic signs and markings. Whether a road intersection needs to set up a signal lamp depends on whether the traffic flow and traffic conflict meet the demand, not necessarily. As for the intersection or road network with signal lights, the signal lights are undoubtedly the obstacles to block and affect traffic flow, and the optimal allocation of "time" can minimize the impact, but its role is limited to "time" optimization and can not be deified as omnipotent. In order to alleviate congestion, we should study landing, that is, space optimization, in terms of traffic flow dispatch, traffic path planning and road plane space optimization.

The essential idea of three-level traffic signal induction is to synchronously optimize the two elements of "time" and "space". It links the three physical traffic signal facilities of "traffic signs, markings and signal lights" together, and integrates communication, sensing and data, so that physical tools can truly replace people (police command). Gestures are also equivalent to the landing application of artificial intelligence in traffic engineering.

2. Introduction of Three-level Traffic Signal Guidance System：

System components: Huawei C-V2X RSU (Road Side Unit) dual-mode roadside unit + Saikang I2V space-time synchronization panel display guide sign + I2V panel display variable lane sign + variable lane marking + signal lamp and its control + Saiyun meteorological monitoring station + encryption computing platform.

The working principle of the system：

Three-level traffic signal guidance: the first level is the upgrading of traditional static information guidance signs to digital time display, variable LED light band and spatio-temporal synchronous luminous guidance signs with fresh light from text and graphics; the second level is the upgrading of traditional curing Lane indication signs to dynamic variable LED luminous guidance signs (more than half of the number of lanes). Variable lane markings without arrows are drawn on the ground of the corresponding lane; the third level is traffic lights.

Firstly, Internet platforms such as Golden Map will obtain various real-time traffic flow data of the road network through the moving vehicle terminals, encrypt mathematical operations through the cloud platform, publish and display the digital time of the first-level guide signs for the distance between the departure place and the destination, and synchronously give green (smooth) color to the Light-Band LED pixel screen. Pass, yellow (slow) and red (congestion) indication information.

Secondly, the lane signs of the second level will selectively change the lane arrows to optimize the allocation of lane space resources according to the traffic flow data of the corresponding downstream sections from the cloud platform. Its function of regulating traffic flow is also equivalent to the gate between the upstream and downstream of the river.

The first two levels of marking information content will digitally send instructions to vehicle OBU via RSU communication equipment on the roadside. Because of the integration of its unique road section meteorological monitoring and panel display luminescence technology system, it can provide long-distance visual performance to artificially driven vehicles in all-weather environments such as bad weather.

Finally, the data synchronization interaction between the third-level traffic lights and the second-level Lane signs, combined with the pedestrian and non-motor vehicle crossing data of intelligent monitoring, makes the corresponding matching time optimization strategy and carries out, and the data information of the traffic lights is also sent to the vehicle OBU through RSU devices.

In the whole operation process of the three-level traffic signal guidance system, traffic flow, traffic signals (signs and traffic lights), road and road network space, moving vehicles, pedestrians and non-motor vehicles, establish the interactive transmission within the regional space, and form the mutual coordination and coordination of consensus mechanism through encryption operation, so as to achieve safety and high efficiency. Effective operational objectives. Because of the formation and use of all data links, storage and operation on cloud platform are transmitted and downloaded via RSU devices, which is safe and reliable.

1. Functional advantages of three-level traffic signal guidance system

This scheme integrates regional traffic guidance, lane function dynamic control and capacity-based time allocation into a system based on the idea of space-time integration and collaborative optimization. At the macro level, combined with guidance signs, guidance information is issued to actively guide drivers to make route selection, so as to balance traffic pressure. At the meso-micro level, the spatial variables such as the number of lanes, lane function and allowable flow direction are combined with the time variables such as green signal ratio, phase sequence and phase difference of signal control to realize the optimal control of space-time integration.

Whether time-based signal control scheme or space-based lane function management, its control variables are the traffic flow passing in unit time. This scheme breaks through the traditional design and control method of time and space isolation, incorporates local and interconnected data of intersections into a system for calculation, and integrates time and space variables into a system for comprehensive consideration. Considering the coordination between nodes and the compatibility between nodes and sections, both macro-based active traffic management and meso-micro space-time integrated collaborative control are adopted to ensure the efficient passage of intersections.

This scheme is feasible and relatively economical. It can not only deal with the daily fluctuation of traffic demand easily and quickly, but also deal with various traffic incidents, large-scale activities and service management and various scenarios.

This scheme has been proved by several authoritative experts of international traffic signal and traffic organization. In the demonstration experiment, it is feasible to apply the new generation of frontier technology to realize data fusion and path planning. It can be predicted that this scheme will play a great role in alleviating traffic congestion in the city, and the transaction is fast and obvious.