Speed display system

Speed display system during the measurement

Dialog display in the Czech Republic

A radar speed sign (short GAA ) is a technical roadside device that serves to indicate its current speed to the driver. The driving speed is recorded by a sensor and shown on a display. These systems are not used for traffic monitoring , as they do not have a camera or license plate recording, and they should not be confused with speed warning systems.

technology

A radar beam from a speedometer of the Pittsford Traffic and Radar is sent at the frequency 24.125 GHz to the approaching vehicles. The speed is determined from the radar reflection and this is displayed in real time on a large LED display with 307 mm character height and 180 ° reading angle. An integrated brightness meter automatically adjusts the LED brightness to the environment. Speeds of 3 to 255 km / h can be processed, with a measuring distance of up to approx. 80 meters (260 feet ), the accuracy is specified with ± 3%.

General data can be stored in an internal memory for statistical evaluations without individual road users being able to be identified. The data memory can be read out via Bluetooth .

purpose

Speed display systems are used to make vehicle drivers aware of their possibly excessive speed through the large display of the measured speed. According to the manufacturer, the display , which can be seen from a great distance, is supposed to bring about a social component , since all bystanders, even at a great distance, can see that the measured speed is exceeded. Special versions of the display system can be equipped with motifs for children and text messages - such as "TOO FAST" or "THANK YOU". Depending on the model, multi-colored number displays (green for okay and red for too fast ) are also possible.

In the study Evaluation of Dynamic Speed Feedback published in 2010, the Accident Research of Insurers (UDV) carried out a comparison of these dynamic speed displays with the so-called dialog display. Although the dialogue display does not show the current speed and only praises and rebukes it by showing "Thank you" and "Slow", there were stronger and permanent decreases in average speeds.