On the implementation of the latest technical solutions for automatic photo and video recording of traffic violations.
From July 1 of this year, it is planned to gradually introduce systems for automatic photo and video recording of traffic violations and the administration of fines in the area of traffic safety violations.
This means the implementation of intelligent video surveillance systems that allow for the automatic recording of such violations as, for example, speeding, driving through a red light, driving in the oncoming lane, etc., with subsequent sending of a demand for payment of a fine to the car owner by mail. Such systems have been implemented and operate in European countries and are an effective means in the fight for road safety, as well as preventing corruption when issuing fines and increasing the productivity of the traffic police.
This article will tell about typical tasks that will be solved with the help of video analysis systems of traffic flows and the existing limitations in their use. The most advanced technical means to date, developed and produced by the domestic company «Vokord», are described. This company has taken on the burden of implementing systems of teleautomatic control of the road situation on highways, fully satisfying the presented concepts of ensuring road safety (and the technical requirements developed within the framework of these concepts).
Generally speaking, the task of video traffic control includes the related tasks of detecting traffic violations by a vehicle using video analysis algorithms and recognizing the state registration plate of the violator. At the same time, it is interesting for the traffic police to have the ability to recognize the numbers of all passing cars for automatic comparison with the stolen car database. Another useful feature embedded in the teleautomatic control system is the analysis of traffic flow statistics (counting the number of cars passing per unit of time, calculating the density and average speed of the flow). In addition, such video surveillance systems will allow identifying the culprits of accidents, as well as monitoring the speed limit.
In practice, there are two main options for using video surveillance cameras — on a straight high-speed section of the road and at intersections. The main task of video surveillance on a straight section of the road is to detect speeding and recognize a car's license plate. Today, there is a practice of using analog video surveillance cameras that are installed on a so-called «U-shaped» support, one camera per lane. The cameras are aimed frontally at approaching (moving away) cars. This approach has 2 serious problems associated with the small size of the control zone of traditional analog cameras:
- cars moving between traffic lanes (along the markings) do not fall into the field of view of any of the cameras.
- The radar speed measurement zone does not coincide with the license plate recognition zone, so if a car changes lanes, the system incorrectly identifies the license plate or cannot identify the violator's license plate at all
An alternative to using analog cameras is the high-resolution digital camera VOCORD NetCam, manufactured by Vocord, which allows you to capture several traffic lanes simultaneously and obtain images of cars (and license plates) with a resolution several times higher than that of analog cameras. Due to the high resolution, VOCORD NetCam cameras can be installed on L-shaped supports. Digital cameras operate under the control of the VOCORD Traffic teleautomatic traffic control system. It should be noted that the VOCORD Traffic system can operate with both VOCORD NetCam digital cameras and conventional analog video cameras. VOCORD NetCam cameras are available with a resolution of 1.3 to 5.1 megapixels. Cameras with a resolution of 1.3 and 3.1 megapixels are most suitable for traffic analysis tasks.
The first pilot projects use 1.3 megapixel cameras. Such a camera can simultaneously capture two traffic lanes. Two Doppler radars are connected to the serial RS-232/485 port of the video camera. After a car appears in the field of view of the video camera, the VOCORD Traffic system commands the radar to measure the speed. The zone in which the car number is captured and recognized is approximately 25 m. Under these conditions, the maximum speed at which the system can recognize the number is 140 km/h. The main task of installing a video monitoring system at an intersection is to detect driving through a red light and recognize the number of the violator's car. Each road petal should be monitored by its own video camera (or group of video cameras). In some cases, separate cameras may be required to recognize numbers on the approach of cars to the intersection. This is due to the fact that for number recognition, the maximum installation angle of the VOCORD NetCam digital camera in the vertical plane should not exceed 20°, and in the horizontal plane – 30° (When using an analog camera, these requirements are even stricter.) At the same time, to detect violations of traffic rules at road intersections, such as driving through a red light, making a U-turn in the wrong place, crossing a solid line, etc., it is necessary to install cameras directly above the intersection.
To control driving through a red light, integration with the traffic light controller is performed.
Using the video monitoring system at night presents a certain difficulty.
In traditional systems, this problem is solved by installing floodlights operating in the visible range. This approach has two significant drawbacks: oncoming light blinds drivers and the control system becomes a potential source of new accidents, and, in addition, floodlights consume a lot of power (about 500 W), which creates difficulties when connecting the system and increases the cost of its operation. To ensure round-the-clock traffic control, the Vocord company produces infrared models of VOCORD NetCam cameras. To ensure operation in the dark, specialized strobe IR floodlights synchronized with cameras are installed. Due to the high sensitivity of the cameras and the strobe mode of the floodlights, the power consumption is significantly reduced (less than 10 W), in addition, the floodlights operate in the near IR range and do not interfere with drivers. If, in addition to recognizing the number and make of the car, it is necessary to determine its color, then in addition to the IR cameras, a conventional color analog camera of high sensitivity is installed. This camera is used as an overview camera, the image from this camera can be transmitted to the surveillance center for visual control of the situation and recorded in a long-term storage archive. This is especially useful for analyzing controversial situations, since in this case, in addition to photographs taken by high-resolution cameras, the system stores a video clip that allows you to track the entire dynamics of the violation.
In conclusion, it is worth highlighting a very important aspect of the practical use of video monitoring systems for traffic flow — developed hardware solutions intended for use in outdoor conditions.
VOCORD NetCam video surveillance cameras (as well as analog video cameras) placed in a hermetic housing can be connected to special servers for outdoor use VOCORD StreetServer, which have a dust and moisture protection class of IP68 and a temperature range from -50 °C to +50 °C. In principle, it is possible to connect up to 4 VOCORD NetCam cameras to one server. It is possible to connect 2 VOCORD NetCam cameras to a standard configuration server based on a Core 2 Duo processor.
An autonomous intelligent element of the VOCORD DigiFlow video surveillance system based on the VOCORD NetCam video camera has also been developed and is being manufactured. VOCORD DigiFlow is a computer platform combined with a high-resolution digital camera VOCORD NetCam in a single hermetic housing for outdoor use. Connection to the distributed video surveillance system is carried out using an IP network.
This equipment is sufficient for flexible design of video surveillance systems based on digital and analog cameras, taking into account specific requirements and possibilities for installation at a specific facility. As a final thesis, I would like to make a statement that the installation of such systems requires certain financial investments, significantly exceeding the cost of conventional video surveillance security systems. At the same time, minimizing the cost of the complex can be achieved at the expense of the efficiency of the system.