Identification of a railroad crossing can be done by using two major types of railroad crossing signage: Passive signs - Signs that alert motorists that they are approaching a highway-rail grade crossing. Advance Warning Signs: A public highway-rail crossing must be identified with a round, yellow advance warning sign. These are specifically for side streets.  Pavement Markings: The warning is painted on the road surface and generally starts at the advance warning sign and ends with a stop bar near the crossing. Active signs - These are electronic devices that warn drivers about an upcoming rail crossing. Installation of flashing lights or flashing lights with gates at a crossing along with the railroad crossing signs (Crossbuck/Stop/Yield/Number of Tracks) makes for Active Warning Signs. Individual states make the decision about which crossings require active warnings. The devices can include -  Flashing red lights – with or without bells to alert the driver of an approaching train. Flashing red lights and gates: To alert the driver of an approaching train, but have a red/white or a black/white gate connected which comes down to block the track.  Barricade of flashing lights: This is specifically designed to reach across the entire road and all traffic lanes so all people can be aware on multi-lane roads that a train is approaching the cross-section.