KR20060061753A - Variable traffic information display system and control method thereof - Google Patents

Abstract

The present invention relates to a variable traffic information display system and a method of controlling the variable traffic information display system which can be displayed automatically or manually by changing the maximum speed limit according to a weather condition. The variable traffic information display system of the present invention has a maximum speed limit according to a weather condition. And a central signal control device for transmitting the relevant traffic information to the variable speed display device, and a variable for receiving the information by wireless communication with the central signal controller and outputting the maximum speed limit or the maximum speed limit and related traffic information to the display module. It consists of a speed display device, and is configured to display and control the maximum speed limit and related traffic information for the relevant weather condition in an automatic or manual manner according to the operation mode divided into automatic / manual / semi-automatic / emergency mode. do.

Traffic, Signs, Variable, Severe Weather, Climate

Description

Variable traffic information display system and control method

1 is a block diagram of a variable traffic information display system according to the present invention;

2 is a block diagram of a central signal control apparatus according to the present invention;

3 is a flowchart illustrating a control operation of the central signal control apparatus in the variable traffic information display system according to the present invention;

4 is a view showing a conventional maximum speed limit traffic sign and its installation example,

5 is a diagram illustrating a format in which a maximum speed limit or maximum speed limit and related traffic information are displayed by a variable speed display device according to the present invention;

6 is a view showing the configuration of a variable speed display device according to the present invention;

7 is a view showing a display aspect of information displayed through the variable speed display device according to the present invention;

8 is a view showing various use states of the variable speed display device according to the present invention;

9 is a table showing a legal maximum speed deceleration table according to a weather condition.

According to the present invention, by displaying a predetermined legal maximum speed limit of a vehicle to a driver using a variable speed display device according to a weather condition at a road traffic authority located at a remote location, visibility reduction due to snow, rain, fog, etc. and sign readability deterioration The present invention relates to a variable traffic information display system and a control method thereof capable of eliminating traffic accidents, inducing compliance with safety speed, and preventing and preventing traffic accidents.

As shown in Fig. 4 (a), (b), the conventional traffic sign is a simple plate-shaped sign using a metal panel, by expressing the basic legal maximum speed, that is, the "normal maximum speed" set based on the clear weather It is used as a tool. However, this sign had a problem that it could not accurately express the legal speed limit set in order to prevent heavy traffic accidents in the case of heavy rain, heavy snow, and fog, that is, "high weather speed."

Current road traffic laws stipulate a reduction of 20/100 of the maximum speed when there is rain on the road or when snow falls less than 20mm, and the visibility is within 100m due to heavy snow, heavy rain, and fog, or freezing, snowing. Although it is prescribed to decelerate 50/100 of the maximum speed when more than 20mm is piled up, the conventional traffic signs can express the legal maximum speed to the driver in real time or at a predetermined time according to the weather conditions changing frequently. There was no at all.

In order to compensate for this, simple auxiliary signs such as <speed caution> and <slow down in rain> are intermittently installed, but they are not a simple solution due to simple warnings and cautions. In the past, depending on the driver's conscience and compliance spirit, he had no choice but to voluntarily comply with the 20% to 50% deceleration regulations.

In addition, speeding surveillance cameras installed on the roads to prevent large catastrophes caused by exceeding specified speeds and to control speeding vehicles, like the conventional road signs, are based on a clear climate, regardless of the road surface and weather conditions. It is fixed at "the highest speed in peacetime", and it is installed to photograph only the violations, and it has been pointed out that a speeding countermeasure for urgent weather and fog should be prepared urgently.

The present invention has been made to solve the above problems, a variable traffic information display system that can change the information, such as the maximum speed limit displayed on the traffic signs by using a wireless communication in a control center in a road traffic related organizations located in remote places; It is an object to provide a control method.

In order to achieve the above object, the variable traffic information display system of the present invention comprises: a communication module for transmitting and receiving control information by a wireless communication method from a central signal control apparatus; A main control module connected to the communication module to generate a control signal for displaying the maximum speed limit information and the related traffic information received through the communication module from the central signal controller on the display module; A display control module connected to the main control module and converting the maximum speed limit or the maximum speed limit and related traffic information into an electric signal according to various scenarios according to a control signal from the main control module; A display module connected to the display control module and displaying a maximum speed limit or a maximum speed limit and related traffic information according to an electric signal from the display control module; At least one variable speed display device having a power supply unit connected to each component of the device to supply power;

As a device for controlling the display information of the variable speed display device is installed in the jurisdiction of road traffic related organizations in the region where the variable speed display device is installed,

A mode setting module for setting by the administrator to any one of automatic / manual / semi-automatic / emergency modes; An external signal input module configured to receive information from an administrator when information is input from an administrator according to a set mode; Connected to the mode setting module and the external signal input module, the maximum limit to be displayed on the display module based on the information from the external real-time weather information sensor or information input through the external signal input module according to the set mode A control module for generating speed information and related traffic information; Central signal control having a communication module for receiving weather information from an external real-time weather information sensor and transmitting the weather information to the control module, and transmitting the maximum speed limit information and related traffic information from the control module to the variable speed display device. It is characterized by consisting of a device.

In addition, when the automatic mode is selected through the mode setting module, the control module of the central signal control apparatus collects real-time weather information from the real-time weather information sensor and analyzes the weather information, and thus the weather condition is preset. If it is determined that the threshold is exceeded, generate a new maximum speed limit and related traffic information corresponding to the weather condition; When the manual mode is selected through the mode setting module, receives a maximum speed limit and related traffic information input through an external signal input module from an administrator; When the semi-automatic mode is selected through the mode setting module, the weather information is checked from the real-time weather information detector every predetermined time to change the maximum speed limit and the relevant traffic information only when a weather result of a predetermined level or more is observed over a predetermined number of times. ; Regardless of which of the automatic / manual / semi-automatic modes is set, when a heavy rain or localized heavy rain is detected from the real-time weather information sensor or an emergency mode is selected through the mode setting module, a preset emergency maximum is set. Characterized in that it changes to the speed limit and related traffic information.

On the other hand, the control method of the variable traffic information display system according to the present invention, the central signal control device for transmitting the maximum speed limit and the related traffic information according to the weather conditions to the variable speed display device, and the wireless communication with the central signal control device A control method of a variable traffic information display system comprising a variable speed display device for receiving the information and outputting a maximum speed limit or a maximum speed limit and related traffic information to a display module, wherein the display module of the variable speed display device is in a clear weather. Displaying a legal maximum speed limit of the first step; A second step of checking a mode set by an administrator in a control module of the central signal control apparatus; According to the result of the second step, in the control module of the central signal controller, (a) when the setting mode is automatic mode, after collecting and analyzing weather information measured in real time from the real-time weather information sensor, Determining whether the conditions for changing the maximum speed limit are satisfied or not, (b) If the setting mode is the manual mode, receives the maximum speed limit and related traffic information input through the external signal input module from the administrator, and (c ) If the setting mode is the semi-automatic mode, it is determined whether the conditions for changing the maximum speed limit are satisfied by changing parameters related to the weather information collection / analysis and the speed change condition from the real-time weather information sensor, and (d) the setting mode. A third step of retrieving a preset emergency maximum speed limit and related traffic information when is an emergency mode; A fourth step of determining, according to the result of the third step, to change or maintain the maximum speed limit; And a fifth step of transmitting the changed maximum limit speed to the variable speed display device when the maximum speed limit is changed according to the result of the fourth step.

In addition, in the control method of the above-described variable traffic information display system, if the weather information is collected from the real-time weather information sensor throughout the first to fifth steps, and it is determined that heavy rain or localized heavy rain occurs, It is another aspect of the present invention that the apparatus further includes the step of retrieving a predetermined emergency maximum speed limit and related traffic information without delay, and transmitting the information to the variable speed display device without delay.

Hereinafter, a variable traffic information display system and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a variable traffic information display system according to the present invention.

As shown, the variable traffic information display system according to the present invention is a central signal control device installed in a road traffic related organization and transmitting control information for controlling display information of a display module according to a weather condition by a wireless communication method ( 20) and at least one variable speed display device 10 which receives control information from the central signal control device via wireless communication and changes and displays the maximum speed limit and related traffic information.

In detail, the variable speed display device 10 is a communication module 11 that transmits and receives control information from a central signal control device by a wireless communication method, and is connected to the communication module and transmitted from the central signal control device through a communication module. A main control module 12 for generating a control signal for displaying the received maximum speed limit information and related traffic information on the display module; and a maximum speed limit or maximum value depending on a control signal from the main control module. A display control module 13 for converting a speed limit and related traffic information into an electric signal so as to be displayed on the display module in various ways; and a maximum speed limit according to the electric signal from the display control module and connected to the display control module. A display module 14 for displaying the highest speed limit and associated traffic information, The power supply unit 15, which is connected to each component of the device and supplies power, is configured in a form embedded in the enclosure forming the outline of the device.

The enclosure is designed to safely protect the components of the device against various weather changes on the road such as snow, rain, wind, cold, and heat, and to achieve the appearance of the device.The material is aluminum, steel plate, plastic, etc. It is not particularly limited. In particular, the interior of the enclosure can be equipped with a thermostat to maintain a constant temperature and a heat dissipation fan for discharging the internal heat to the outside of the display module to play a role of protecting the device components against various weather changes. Additional front panels may be provided with a shading plate or other additional device to prevent direct sunlight.

The power supply unit 15 is a device for stably supplying power to the entire variable speed display device 10 of the present invention. The power supply unit 15 may arbitrarily select an AC power supply or a DC power supply. Internal rectifier can convert AC power to DC. In addition, a power supply device including a solar cell or a wind generator may be applied in a mountainous area or a remote area, an area where frequent power failures occur due to frequent landslides, or other areas where current supply is difficult.

The communication module 11 is configured to exchange various control information with the central signal control device 20 installed in a road traffic related organization in a wireless communication method. For example, a wireless communication method using a wireless LAN, CDMA, RF, TRS, WLL, etc. may be selectively applied within existing technical limits as necessary.

The main control module 12 is the maximum speed limit information received from the central signal control device through the communication module 11, and the relevant traffic information, such as <slowly>, <rain road deceleration operation>, <50% heavy rain deceleration> The related image information is transmitted to the display control module 13.

The main control module 12 controls the function so that the current legal maximum speed limit can be accurately expressed by automatically adjusting the brightness of the module of the variable display embedded in the traffic display device according to the light intensity or the brightness of the road. It can be provided. In addition, it may be additionally provided with a function to control the normal operation of various additional devices, such as a thermostat to maintain a constant temperature so as to safely protect the device components against various weather changes, and a radiating fan to discharge the internal heat out.

The display control module 13 is connected to the main control module 12 to display digital character information such as speed change information and related traffic guidance information received through the main control module 12 to the variable display module. It is a structure that converts into a signal.

In addition, the display module 14 is connected to the display control module 13, a display device for finally expressing the electric signal received through the form of a letter, symbol, picture, etc., including an LED, an organic EL It can be configured by selecting from various light emitting devices.

In addition, the central signal control device 20 is installed in the jurisdiction of road traffic-related organizations in the region where the variable speed display device 10 is installed, and automatically or manually determine the legal maximum speed limit of the roads within the jurisdiction according to weather changes. An apparatus for controlling display information of a variable speed display apparatus by wireless communication in a center, and as shown in FIG. 2, a mode setting module 21 for setting by the administrator to any one of automatic / manual / semi-automatic / emergency modes. And, if information is required from the administrator according to the set mode, the external signal input module 23 receives the information from the administrator, the mode setting module and the external signal input module is connected, according to the set mode On the basis of the information from the real-time weather information sensor 30 or the information input through the external signal input module, the display module to be displayed on the display module The control module 22 generates speed limit information and related traffic information, and receives weather information from an external real-time weather information sensor, and transmits the weather information to the control module, the maximum speed limit information and the related traffic information from the control module. It consists of a configuration having a communication module 24 for transmitting to the variable speed display device 10.

The communication module 24 of the central signal control device 20 is connected to an external speed monitoring camera 40, an intelligent traffic management system (ITS), a road traffic control center, and the like to transmit control information regarding the maximum speed limit. can do.

More specifically, when the automatic mode is selected through the mode setting module 21, the control module 22 of the central signal control device 20 collects real-time weather information from the real-time weather information sensor, and then provides weather information. If it is determined that the weather condition has exceeded the preset threshold, the controller operates to generate a new maximum speed limit and related traffic information corresponding to the weather condition. In addition, when the manual mode is selected through the mode setting module 21, and receives the maximum speed limit and related traffic information input through the external signal input module from the administrator, when the semi-automatic mode is selected through the mode setting module 21 In order to check the weather information every predetermined time from the real-time weather information detector to operate only to change the maximum speed limit and the relevant traffic information only when a predetermined number of weather results more than a predetermined number of times is observed. In addition, regardless of whether the automatic / manual / semi-automatic mode is set, when the heavy rain or localized heavy rain is detected from the real-time weather information sensor or the emergency mode is selected through the mode setting module 21, And generate a control signal to change to a preset maximum speed limit and related traffic information in an emergency.

The real-time weather information detector 30 is a device that automatically detects various weather factors, such as rain, snow, temperature, fog, can be configured as a weather information collector that is already installed and operating, including rain gauge, steel design and analog Alternatively, various weather information sensing devices and technologies that can be applied within all existing technical limits, such as digital thermometers, hygrometers and fog detectors, may be selectively applied. The real-time weather information detection unit 30 automatically detects rainfall, snowfall, etc. in an analog or digital manner every one minute or at a predetermined time or at a predetermined time, for example, and communicates with the communication module 24 of the central signal controller 20. It plays a role of delivering to).

3 is a flow chart showing the control operation of the central signal control apparatus in the variable traffic information display system according to the present invention, the variable speed according to the control mode (automatic / manual / semi-automatic / emergency mode) set by the administrator in the central signal control apparatus The process of changing the maximum speed limit and related traffic information to be displayed on the display device is shown.

That is, the control method of the variable traffic information display system of the present invention includes the first step of displaying the legal maximum speed limit in clear weather on the display module of the variable speed display device 10; A second step of checking a mode set by an administrator in the control module of the central signal control apparatus 20; According to the result of the second step, in the control module of the central signal control apparatus 20, (a) when the setting mode is the automatic mode, after collecting and analyzing the weather information measured in real time from the real-time weather information sensor, It is determined whether the conditions to change the maximum speed limit of the road are satisfied. (B) If the setting mode is the manual mode, the maximum speed limit and related traffic information inputted through the external signal input module are received from the administrator. , (c) If the setting mode is semi-automatic mode, it is determined whether the conditions for changing the maximum speed limit are satisfied by changing parameters related to weather information collection / analysis and speed change conditions from the real-time weather information sensor. A third step of searching for a preset emergency maximum speed limit and related traffic information when the setting mode is an emergency mode; A fourth step of determining, according to the result of the third step, to change or maintain the maximum speed limit; According to the result of the fourth step, when the maximum speed limit is changed, a fifth step of transmitting the changed maximum speed limit to the variable speed display apparatus.

In the variable traffic information display system of the present invention, the control module 22 of the central signal control apparatus 20 controls to display the default statutory maximum speed in clear weather as soon as power is supplied as the first step. . In the next second step, the administrator checks the operation mode set by the external signal input module 23.

In the third step, the maximum speed limit and the related traffic information to be displayed on the variable speed display apparatus 10 are determined according to the result of the second step, and the specific control operation divided into automatic / manual / semi-automatic / emergency modes is performed. Do this.

First, when the automatic mode is set, after collecting the real-time weather information sent from the real-time weather information detector 30, and analyzes the information in real time using its own algorithm, changing the legal maximum speed limit of the road Check whether sufficient conditions have to be met. As a result, if it is determined that the condition is satisfied, after the fourth step of determining that the legal maximum speed limit displayed on the variable speed display device 10 is changed, the changed speed information and related traffic information are displayed. Proceeds to the fifth step of transmitting to the communication module (11) of.

In the real-time analysis method, for example, when it is determined that the weather condition exceeds a predetermined reference value as a result of analyzing the obtained weather information, the legal maximum speed deceleration table or the current road traffic according to the weather condition as shown in FIG. 9. The new maximum speed limit is displayed in accordance with the relevant legal regulations.

In addition, the control module 22 may generate a control signal for displaying related traffic information or various related image information, such as <slowly>, <rainy road deceleration operation>, <50% rain reduction>.

In addition, when the manual mode is set, an external signal is input to the maximum speed limit and related traffic information input by the manager or staff in charge of changing and managing the maximum speed limit according to the road traffic regulations according to the weather conditions in the jurisdiction. After the third step of receiving through the module 23 and the fourth step of determining the maximum speed limit change, the changed speed information and related traffic information are transferred to the communication module 11 of the variable speed display device 10. Proceed to the fifth step of transmitting. In the case of manually changing the maximum speed limit as described above, the road traffic official may report or report the road conditions in the jurisdiction through reporting or reporting, or obtain information by using weather information collectors such as rainfall precipitation system, river design, and fog meter. After that, the road traffic peak speed limit manager can analyze these data in three dimensions to determine when to change the maximum speed limit, thereby making more scientific and rational decisions.

In addition, when the semi-automatic mode is set, the third step determines whether the condition for changing the maximum speed limit is satisfied by changing parameters related to weather information collection / analysis and speed change conditions from the real-time weather information sensor. Such a control mode is suitable when there is a concern about congestion or congestion caused by changing the maximum speed too frequently due to the changeable weather. This is to provide flexibility in responding to excessive weather fluctuations, such as changing the speed only when continuously observed.

In addition, when the emergency mode is selected, in the third step, after retrieving the preset maximum speed limit and related traffic information in emergency, the fourth step of determining the change of the maximum speed limit, and the like, and the change speed information, etc. Proceeds to the fifth step of transmitting to the communication module 11 of (10). The emergency mode may be selected when agility is required to respond to an emergency situation such as sudden heavy rain or localized heavy rain.

In addition, the control method of the variable traffic information display system of the present invention collects weather information from the real-time weather information sensor throughout the first step to the fifth step, if it is determined that heavy rain or localized heavy rain occurs The method may further include retrieving a predetermined emergency maximum speed limit and related traffic information without delay, and transmitting the information to the variable speed display device without delay.

5 (a) to 5 (d) illustrate a format in which the maximum speed limit or the maximum speed limit and related traffic information are displayed by a variable speed display field of the variable traffic information display system of the present invention.

As shown, in the variable speed display device of the present invention, the display module 14 has various shapes such as a circle (Fig. 5 (d)) or a rectangle (Fig. 5 (c)) similar to the existing road traffic guide signs. Can be configured. In addition, as shown in FIGS. 5A and 5B, the maximum speed limit display unit and the associated traffic information display unit may be provided. In this case, both the maximum speed limit display unit and the related traffic information display unit may provide variable information. Among them, in particular, the relevant traffic information display unit may be made of a material such as steel, not variable information, which is changed according to weather conditions, to display fixed traffic information related to traffic safety. In this case, the information displayed on the relevant traffic information display unit is configured such that various information related to traffic safety including <rainy weather speed 20% deceleration> <ice road driving attention> is displayed in the form of text, symbols, images.

6 shows a configuration of a variable speed display device 10 according to the present invention, comprising: a control circuit part including a communication module 11, a main control module 12, and a display control module 13 in a housing part; A display module 14; It shows a form in which the power supply unit 15 is built. Since the variable speed display apparatus 10 according to the present invention is controlled by a wireless communication method by an external central signal control apparatus 20 to display change speed information and the like, the speed display apparatus 10 installed on the roadway is provided. It has the advantage of being lightweight and compact in appearance, easy to install, and low in manufacturing cost.

7 is a diagram illustrating a format in which a speed limit and related traffic information are displayed by the variable traffic information display system of the present invention. If various display scenarios are configured to properly configure the display operation program so that the driving speed can be clearly and accurately conveyed to the driver in bad weather conditions, it may have an effect that can greatly contribute to road traffic safety.

8 (a) to (d) are views showing various usage states of the variable speed display device according to the present invention. As shown in the figure, a circular or square display module and a variable or fixed display module may be variously combined.

In the above, the present invention has been shown and described with respect to certain preferred embodiments. However, the present invention is not limited only to the above-described embodiments, and those skilled in the art to which the present invention pertains can make various changes without departing from the technical spirit of the present invention described in the following claims. You can do it.

According to the variable traffic information display system of the present invention and a control method thereof, the legal maximum speed limit of a vehicle on the road can be changed to wireless communication in accordance with the road traffic-related laws in accordance with the weather conditions in the pipe automatically or manually in remote places in bad weather. Therefore, there is an effect that can greatly reduce the large traffic accidents caused by bad weather.

In addition, according to the variable traffic information display system and the control method of the present invention, it is possible to present an objective, scientific, and reasonable standard for the worst weather speed limit violations in which the basis of realistic crackdown and punishment is unclear. By using surveillance cameras or speed detection devices, speeding up drivers can be controlled in bad weather conditions.In bad weather, speeding up drivers can be prevented. There is an effect that can greatly reduce human injury.

Claims (7)

A communication module for transmitting and receiving control information from the central signal controller by a wireless communication method; A main control module connected to the communication module to generate a control signal for displaying the maximum speed limit information and the related traffic information received through the communication module from the central signal controller on the display module; A display control module connected to the main control module and converting the maximum speed limit or the maximum speed limit and related traffic information into an electric signal according to various scenarios according to a control signal from the main control module; A display module connected to the display control module and displaying a maximum speed limit or a maximum speed limit and related traffic information according to an electric signal from the display control module; At least one variable speed display device having a power supply unit connected to each component of the device to supply power; As a device for controlling the display information of the variable speed display device is installed in the jurisdiction of road traffic related organizations in the region where the variable speed display device is installed, A mode setting module for setting by the administrator to any one of automatic / manual / semi-automatic / emergency modes; An external signal input module configured to receive information from an administrator when information is input from an administrator according to a set mode; Connected to the mode setting module and the external signal input module, the maximum limit to be displayed on the display module based on the information from the external real-time weather information sensor or information input through the external signal input module according to the set mode A control module for generating speed information and related traffic information; Central signal control having a communication module for receiving weather information from an external real-time weather information sensor and transmitting the weather information to the control module, and transmitting the maximum speed limit information and related traffic information from the control module to the variable speed display device. Variable traffic information display system comprising a device. According to claim 1, wherein the control module of the central signal control device, When the automatic mode is selected through the mode setting module, after collecting weather information from the real-time weather information detector in real time, and analyzing the weather information, if it is determined that the weather condition exceeds a preset reference value, the weather condition Create a new maximum speed limit and associated traffic for When the manual mode is selected through the mode setting module, the maximum speed limit and the related traffic information input through the external signal input module are received from the administrator. When the semi-automatic mode is selected through the mode setting module, the weather information is checked from the real-time weather information detector every predetermined time to change the maximum speed limit and the relevant traffic information only when a weather result of a predetermined level or more is observed over a predetermined number of times. , Regardless of which of the automatic / manual / semi-automatic modes is set, when a heavy rain or localized heavy rain is detected from the real-time weather information sensor or an emergency mode is selected through the mode setting module, a preset emergency maximum is set. Variable traffic information display system, characterized in that for changing the speed limit and the associated traffic information. The method of claim 2, The communication module of the variable speed display device may use one or more media selected from among wireless LAN, CDMA, RF, TRS, and WLL as a wireless communication medium in communication with a central signal control device. The method of claim 3, The main control module of the variable speed display device, It automatically adjusts the brightness of the display module that displays the maximum speed limit or the maximum speed limit and related traffic information according to the light intensity of the sun or the brightness of the road, and self-diagnoses the operation status of each component of the device. Variable traffic information display system. The method of claim 4, wherein The communication module of the central signal control device is connected to an external speed monitoring camera, an intelligent traffic management system (ITS), a road traffic control center, and the like, and transmits the control information regarding the maximum speed limit. . Central signal control device for transmitting the maximum speed limit and related traffic information according to the weather condition to the variable speed display device, and receiving the information by wireless communication with the central signal control device to the maximum speed limit or the maximum speed limit and related traffic information In the control method of a variable traffic information display system comprising a variable speed display device for outputting a to the display module, Displaying a legal maximum speed limit in clear weather on a display module of the variable speed display device; A second step of checking a mode set by an administrator in a control module of the central signal control apparatus; In the control module of the central signal controller according to the result of the second step, (a) When the setting mode is automatic mode, after collecting and analyzing the weather information measured in real time from the real-time weather information detector, it is determined whether the conditions for changing the maximum speed limit of the corresponding road are satisfied, (b) If the setting mode is the manual mode, the administrator receives the maximum speed limit and related traffic information input through the external signal input module from the administrator. (c) When the setting mode is a semi-automatic mode, it is determined whether the conditions for changing the maximum speed limit are satisfied by changing parameters related to weather information collection / analysis and speed change conditions from the real-time weather information sensor. (d) a third step of retrieving a preset emergency maximum speed limit and related traffic information when the setting mode is an emergency mode; A fourth step of determining, according to the result of the third step, to change or maintain the maximum speed limit; And a fifth step of transmitting the changed maximum limit speed to the variable speed display device when the maximum speed limit is changed according to the result of the fourth step. The method of claim 6, Collecting weather information from the real-time weather information detection unit throughout the first step to the fifth step, if it is determined that heavy rain or localized heavy rain has occurred, it is not bound to the step being executed, it is the highest in the emergency set in advance without delay And retrieving the speed limit and the related traffic information, and transmitting the information to the variable speed display device.

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