Countdown clocks revealed at select R line stations

At least now you’ll know how long you’ll be waiting.

The MTA unveiled countdown clocks at select R train stations on Monday, July 11, giving commuters an easy and accurate way of finding the arrival time of the next train.

The new clocks rely on existing wireless networks in the subway stations, as well as cloud computing, to provide a relatively accurate readout, according to the agency. Four Bluetooth receivers placed in each station— two at each end of the platform—work in tandem with four Bluetooth devices that have been installed in the first and last cars of each train running on the R line. As each train enters and departs the station, the receivers communicate with the devices and uses its arrival and departure time at which the train will enter the next station.

Besides being available in the form of physical clocks, estimated times are also available on the MTA’s Subway Time smartphone application, as well as online at apps.mta.info/traintime.

Countdown clocks will also become available for 18 stations on the N line, 13 stations on the D line and 21 stations on the F line beginning in November 2017. According to the MTA, countdown clocks will be installed and activated in all 269 letter-line stations by the end of 2017.

This article originally appeared in the Brooklyn Reporter.