Prague testing new system to prevent loss of satellite signal in tunnels

Blanka tunnel, photo: Kamila Schusterová / Czech Radio

The city of Prague started testing a new system that should prevent the loss of satellite signal in the city’s tunnels. The system, which should make life easier for drivers who rely on car-navigation technology, is currently being tested in Prague’s Blanka tunnel. If it proves successful, the municipality wants to install the device in other strategic locations around the city. 

Anyone who drives around Prague using the car-navigation system will be familiar with the announcement about the loss of satellite signal when entering a tunnel.

To prevent the situation from happening in the future, the city of Prague is currently testing a small device, called repeater, in several places of the Blanka tunnel. Adam Scheinherr is the Deputy Mayor for Transport:

“We are currently testing a new, unique system. We will be transmitting a signal from all accessible satellites, such as GPS, but also from the European navigational system Galileo.

“Thanks to the repeater device, the navigation finds a signal and the direct position of the driver. So far, the device has been installed in two locations, one at the exit to Trója and one to Letná.”

Photo: Jiří Groh,  Pixabay / CC0

The system is based on technology which is commonly used in buildings, but its use in transportation structures is not that usual, explains Pavel Šourek, technical director of the company Satra, which is responsible for the installation of the repeaters:

“We want to test these devices in transport constructions. In buildings, these devices are mainly used to identify security forces in an emergency situation.

“We need to find out, what is the range of the repeaters within the tunnel, and how fast they connect to the navigation system, in order to find out how many such devices we need.”

According to Martin Pípa, deputy head of the Technical Road Administration, the device should also help increase the safety of drivers in tunnels. At present, due to the loss of signal, drivers tend to decide about which exit to take at the very last moment. They often make unexpected turns, threating the safety of other drivers.

“Navigations estimate where the vehicles are located. However, if the traffic flow is unstable, the navigation stops working and the drivers lose information about where they are.

“The signal repeaters are used for this purpose. In front of strategic places, where drivers have to decide which exit to take, the GPS signal appears and the navigation system starts working.”

According to the Deputy Mayor for Transport, Adam Scheinherr, the testing of the repeater devices will be evaluated after a month-long testing round. If the system proves to be successful, the City Hall plans to install them in other strategic locations around Prague, especially in front of crossroads as well as in tunnel entries and exits.

Authors: Ruth Fraňková , Adam Bejšovec
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