For anyone who has driven into a tunnel while using GPS for navigation, the loss of satellite signal and map guidance can be disconcerting, particularly when trying to find your way to the correct exit. To help avoid the anxiety and inconvenience such a problem can create, an engineer has developed a set of wireless transmitters, known as Waze Beacons, that can be installed in tunnels to send navigation signals directly to a smartphone or tablet via Bluetooth.
Created by Gil Disatnik, an engineer at the traffic app development company Waze Mobile, Waze Beacons are claimed to be the world's first expandable, cost-effective units able to provide navigation in tunnels. Battery-powered, the beacons are more accurately described as microcontrollers that use Eddystone (a Bluetooth low-energy beacon system developed by Google) to send real-time routes and alerts to connected devices.
Inspired by an incident where Disatnik missed a turn off when driving from Logan Airport in Winthrop, Massachusetts to the city of Boston, as a result of a GPS signal drop out in a tunnel en route, the Waze engineer hit upon the idea of in-tunnel navigation and went about applying his expertise in radio frequency electronics and microcontrollers to develop the Waze Beacons.

Working in tandem with asset tracking solutions company Bluvision, Disatnik and his Waze team built bespoke beacon hardware tailored for use with traveling vehicles specifically in a tunnel environment.
Waze has configured its system to have no proprietary access, rather the navigation services are beamed over Bluetooth free of charge, so that appropriate apps on any smartphone or tablet device can use the technology when navigating tunnels.
With features including live traffic updates and notifications on incidents or accidents within the tunnel being navigated, Waze Beacons are currently available in a handful of tunnels in Pittsburgh, Pennsylvania and Haifa, Israel, with plans to launch in Paris and Rio de Janeiro sometime in the near future.
Source: Waze